Astro Cast

Black Hole Mass Related to Globular Cluster Numbers

2010-09-08T13:56:00.000-04:00

A photo of the jet emitted by the black hole in galaxy M87

The mass a supermassive black hole at the center of a large galaxy has appears to be related to the number of globular cluster that particular galaxy contains, a new report suggests.

The data has been derived from a new investigation of the stars, which indicates that the two are somehow linked. The exact mechanisms underlying this connection are still unclear.

There are many such correlations in astronomy, experts say, even if some are arguably clearer than others. Given that the new connection was observed in several cases, scientists will continue to analyze it until they get to the bottom of it.

One interesting aspect of the new discovery is that it holds more value for some galaxies than for others. Astronomers say that finding out precisely why this happens is yet another mystery that needs solving.

In past studies, astrophysicists demonstrated that supermassive black holes exert numerous influences on their host galaxies, including regulating their growth.

In addition, these SMBH can also influence the total amount of dark matter massive galaxies contain, change the brightness of the bulges spiral galaxies have, and influence the masses of these bulges.

But astronomers also know that the luminosity of a galaxy and the amount of dark matter its halo contains are also influenced by the number of globular clusters the cosmic structure contains.

Researchers wanted to learn whether they could eliminate the intermediaries, and still maintain a direct correlation, between the SMBH and the number of clusters.

According to team leaders Andreas Burkert of the Max Planck Institute for Extraterrestrial Physics, in Germany, and Scott Tremaine, at the Princeton University, this is entirely possible.

The discovery hints at a previously-unknown regulation mechanism. It was confirmed in 13 different instances, the research team says.

Details of the investigation will be published in an upcoming issue of the esteemed scientific journal Monthly Notices of the Royal Astronomical Society.

The journal entry also features a follow-up on the original study, which includes case studies of 33 galaxies. Even with these increased number of instances, the correlation holds true.

Interestingly, it was found that the connection is especially true for elliptical galaxies. For lenticular galaxies, the team failed to uncover any correlation.

No reasons as to why that happens have yet been discovered, Universe Today reports.

Galaxies Caught in Massive Display of 'Cannibalism'

2010-09-08T13:54:00.000-04:00

Stellar streams around the spiral galaxy M63

Astronomers have recently observed a series of large galaxies as they were consuming smaller versions of themselves, in order to increase their bulk and mass.

The fact that galaxies tend to collide and merge with each other is nothing new, and experts have been observing some of these cosmic events for many years.

One of them, the Antennae Galaxies, are even renowned around the world. They were imaged with Hubble a few years back, and have since become the unofficial symbol of galactic mergers.

At this point, astrophysicists believe that even the Milky Way engaged in such behavior in the past, when it started to gobble up smaller, dwarf galaxies in its surroundings.

Traces of those bodies can still be seen today, in the anomalous behavior and number of star clusters located throughout the galaxy, as well as in the properties of the supermassive black hole at its core.

But the new observations show for the first time galactic cannibalism taking place outside of the Milky Way's local neighborhood.

The research group, led by expert David Martinez-Delgado, found that dwarf galaxies appear to be heavily influenced by these collisions, especially as far as their shapes go.

Massive distortions appear, and some of the most common side effects of mergers include the development of tidal tails and tendrils, that completely surround and grasp the larger galaxy.

Martinez-Delgado, who holds a joint appointment at the Max Planck Institute for Astronomy, in Germany, and the Instituto de Astrofísica de Canarias, in the Spanish Canary Islands, also collaborated with amateur astronomers for the research.

The expert says that the recent investigation proved the existence of galactic mergers in galaxies up to 50 million light-years,Space reports.

According to the research team, it would appear that the tidal tails are produced under the incredibly strong gravitational pull that the larger galaxies exert on the near side of smaller ones.

Their appearance is determined by the fact that stars are more distant from the larger galaxy lag behind those who are closer. The latter travel at much higher speeds.

The new scientific research will be published in the October issue of the esteemed Astronomical Journal.

Two Asteroids To Swing Past Earth Today

2010-09-08T13:53:00.000-04:00

Experts at a NASA lab announce that two asteroids will pass close to our planet today, September 8. The two space rocks are in unrelated orbits, the team says, and pose no danger to Earth.

Each of the celestial bodies is a few meters in diameter, and wouldn't have caused any major damage if they were to strike anyway. What's interesting is that they will both move past the planet the same day, even if they come from very different orbits.

The attached graphic reveals the paths that the two asteroids will take as they swing past Earth. When they are nearest, they should become visible to amateur astronomers with moderate-sized telescopes.

Objects of this class, 10-meter-sized near-Earth asteroids, have a very small chance of hitting the planet overall, but a high chance of passing within lunar distance.

In fact, this happens once per day on average. Such a boulder slams into the atmosphere and burns up about once every 10 years.

Astronomers estimate that the undiscovered population of NEO orbiting the solar system in our vicinity could number as much as 50 million members.

The two new objects were discovered on Sunday, September 5, by the Tucson, Arizona-based Catalina Sky Survey, experts at the NASA Jet Propulsion Laboratory (JPL) announce.

“Near-Earth asteroid 2010 RX30 is estimated to be 32 to 65 feet (10 to 20 meters) in size and will pass within 0.6 lunar distances of Earth (about 154,000 miles, or 248,000 kilometers) at 2:51 am PDT (5:51 a.m. EDT) Wednesday,” the team explains.

“The second object, 2010 RF12, estimated to be 20 to 46 feet (6 to 14 meters) in size, will pass within 0.2 lunar distances (about 49,088 miles or 79,000 kilometers) a few hours later at 2:12 pm PDT (5:12 pm EDT),” they add.

Keeping an eye on NEO is extremely important, given the large number of unknown space rocks that lurk in outer space. On top of that, our solar system features two asteroid belts.

Dangerous objects may exist in both of them, and more telescopes should be built to try and detect, identify and analyze them.

NASA's Spitzer and WISE have already been conducting such research for some time, but the sheer volume of work to be done is massive.

NGC 300 Imaged in Exquisite Detail

2010-09-08T13:51:00.001-04:00

Following an observations campaign that lasted several years, astronomers at ESO finally managed to produce the most accurate and detailed image of the superb spiral galaxy NGC 300.

The formation is located relatively close by, in the Sculptor Group of galaxies, and it is widely considered to be one of the most easy-to-observe structures in the Southern Hemisphere.

The recent image was pieced together from a multitude of different observations, taken over a period of a few years, by experts using numerous color filters.

In total, it took about 50 hours of exposure time to collect the data necessary to create this view. The Wide Field Imager (WFI) at the ESO La Silla Observatory, in Chile, was the main instrument used for the job.

The European Southern Observatory has numerous facilities in Chile, a country that houses parts of the Atacama Desert. This is the most arid desert on the face of the planet, and also one of the driest.

Precipitations here are scarce, and clouds are almost unheard of, and this sets the perfect stage for astronomical observations.

This allowed the WFI to observe NGC 300 in exquisite detail, experts say. Other galaxies in the Sculptor Group that have been imaged using ESO telescopes include NGC 55, NGC 253, and NGC 7793.

Generally, the Group inconspicuous, but it is actually the home of numerous interesting galaxies. NGC 300 is no exception in this regard.

In fact, the thing that makes this galaxy is interesting is not some extreme characteristic, but rather the fact that it's perfectly normal.

Given its similarities to our own Milky Way, experts are analyzing it as a means of deriving more data on our home galaxy as well. We can't get out of the Milky Way yet, but we can observe it from a distance.

“The data was acquired over many observing nights, spanning several years,” the ESO experts say.

“The main purpose of this extensive observational campaign was to take an unusually thorough census of the stars in the galaxy, counting both the number and varieties of the stars, and marking regions, or even individual stars, that warrant deeper and more focused investigation,” they add.

“By observing the galaxy with filters that isolate the light coming specifically from hydrogen and oxygen, the many star-forming regions along NGC 300’s spiral arms are shown with particular clarity in this image as red and pink clouds,” the ESO team concludes.

Chaos Plagued the Early Universe

2010-09-08T13:47:00.000-04:00

A new theory proposes that the earliest Universe, which formed immediately after the Big Bang, expanded in the space around it in an extremely chaotic manner.

This is not by far a new idea. It was proposed for the first time more than seven years ago, by Adilson E. Motter, who is a physics expert at the Northwestern University.

At the time when the idea was first conjectured, the physicist did not have the tools needed to prove it.

Now, with the help of a colleague, Motter finally managed to present the world with the mathematical utensils needed to demonstrate the theory rigorously.

Details of the work appear in a paper entitled “(Non)Invariance of Dynamical Quantities for Orbit Equivalent Flows,” which is published in the latest issue of the top-rated Journal Communications in Mathematical Physics.

The mathematical tools work extremely well when applied to the most widely-accepted model of how the Universe came to be.

The main conundrum the physicist was trying to crack is whether chaos is absolute or relative inside systems that are in themselves governed by general relativity.

In these systems, time itself is relative. For the purpose of the work, chaos was determined at the phenomenon by which tiny events lead to very large changes in the time evolution of a system.

The Universe therefore becomes a prime example of a chaotic system. An absolute thing, for example, is the speed of light, which remains the same regardless of where an observer is placed in time and space.

“A competing interpretation has been that chaos could be a property of the observer rather than a property of the system being observed,” says Motter, who is an assistant professor of physics and astronomy at the Northwestern Weinberg College of Arts and Sciences.

“Our study shows that different physical observers will necessarily agree on the chaotic nature of the system,” adds the expert, who is also the author of the new journal entry.

“Technically, we have established the conditions under which the indicators of chaos are relativistic invariants. Our mathematical characterization also explains existing controversial result,” Motter goes on to say.

“They were generated by singularities induced by the choice of the time coordinate, which are not present for physically admissible observables,” he concludes.

Why do we love Hubble.

2010-08-22T22:41:00.001-04:00

Lunar Reconnaissance Orbiter LROC images - August 3-5, 2010

2010-08-09T12:29:00.000-04:00

The following featured images taken by the Lunar Reconnaissance Orbiter Camera (LROC) are now available:

Remnants of the Imbrium impact (Released 3 August 2010)
Mare basalts embayed ejecta structures formed by the massive Imbrium impact.
Concentric crater (Released 4 August 2010)
The inner rim of Gruithuisen K.
A path not taken (Released 5 August 2010)
Mare surface in Sinus Aestuum near a lunar exploration site proposed in the late 1950s.

Hubble: Frenzied star birth in Haro 11

2010-08-09T12:21:00.001-04:00

Haro 11 appears to shine gently amid clouds of gas and dust, but this placid facade belies the monumental rate of star formation occurring in this "starburst" galaxy.

By combining data from the Hubble Space Telescope and ESO's Very Large Telescope, astronomers have created a new image of this incredibly bright and distant galaxy.

The team of astronomers from Stockholm University, Sweden, and the Geneva Observatory, Switzerland, have identified 200 separate clusters of very young, massive stars. Most of these are less than 10 million years old. Many of the clusters are so bright in infrared light that astronomers suspect that the stars are still emerging from the cloudy cocoons where they were born. The observations have led the astronomers to conclude that Haro 11 is most likely the result of a merger between a galaxy rich in stars and a younger, gas-rich galaxy. Haro 11 is found to produce stars at a frantic rate, converting about 20 solar masses of gas into stars every year.

Haro galaxies, first discovered by the noted astronomer Guillermo Haro in 1956, are defined by unusually intense blue and violet light. Usually this high energy radiation comes from the presence of many newborn stars or an active galactic nucleus. Haro 11 is about 300 million light-years away and is the second closest of such starburst galaxies.

The paper describing this result ("Super star clusters in Haro 11: Properties of a very young starburst and evidence for a near-infrared flux excess", by A. Adamo et al.) is available athttp://adsabs.harvard.edu/doi/10.1111/j.1365-2966.2010.16983.x

STEREO Detect Impossibly Fast Solar Eruption

2010-08-09T11:26:00.000-04:00

The twin components of the NASA Solar TErrestrial RElations Observatory (STEREO) mission were recently able to detect one of the fastest and largest solar eruptions in recent history. On August 1, the Sun released a massive amount of matter and radiation, which sped away from the star at a whooping 2.2 million miles per hour. Despite this massive speed, the two spacecrafts were able to detect the event, and send their conclusions back to Earth, where researchers confirmed the discovery.

The large solar flare triggered a massive eruption called a coronal mass ejection (CME). This is one of the most dangerous things that can go on in the star, experts say. CME produce massive amounts of highly-energetic particles, which have the effect of a heavy bombardment on Earth's protective layer, the magnetosphere. The entire force of the ejection was unleashed on our planet on Tuesday, August 3, and the main result was a heavy intensification of the northern lights, the Aurora Borealis. We got off easy this time, solar physicists say, as larger CME can have devastating effects on our infrastructure.

Representatives of the American space agency said in a recent statement that “these kinds of eruptions are one of the first signs that the Sun is waking up and heading toward another solar maximum expected in the 2013 time frame.” The star functions in 11-year-old cycles, each of which contains a solar maximum and a minimum. These periods are named according to the amount of solar activity (sunspots, solar flares, CME) that takes place on the Sun's surface. Over the past two years, the star should have exited the minimum stage, and begin resuming its activity. But the minimum persisted, and it's only now that the Sun is beginning to show signs of recovery.

STEREO is in a unique position to conduct very accurate observations of the solar surface, given that its twin spacecrafts allow for it to look at the Sun in 3D. This allows solar physicists to get a depth-of-view in their studies, that is impossible with any other telescope. Not even the Solar Dynamic Observatory (SDO), the most advanced Sun-watching instrument, can produce 3D views of its targets. STEREO is capable of doing this because its components fly apart from each other, providing independent views of the same event from two vantage points, Space reports.

Santa Fe Was Impacted by Huge Asteroid

2010-08-09T11:24:00.001-04:00

Between 1.2 billion and 330 million years ago, the area near Santa Fe, New Mexico, was the site of a major asteroid impact. The conclusion belongs to a new study, which looked at an exposed mountain wall. The feature exposes a number of rock layers that look all the same to the eye of profane individuals, but which provide geologists with a wealth of data about Earth's distant past. It is estimated that the original impact crater was no less than between 6 and 13 kilometers in diameter, Space reports.

The reason why the timing of the impact cannot be determined with more accuracy is an anomaly known as the “Great Unconformity.” This means that the rock layers corresponding to the period stretching between 1.2-1.6 billion years and 330 million years ago are missing. This may have happened for a variety of reasons, but the leading theory is that a sea existed at this location a long time ago. This and other natural factors such as water receding, erosion, winds and so on, destroyed the rocks, which only began depositing ago when seas moved back on, 330 million years ago.

It was then that the first sediments were laid down again. This is why 1.2 billion year old layers of rock now lie directly underneath much newer ones. “We need an army of scientists and graduate students studying this site, over many, many years. It could take several lifetimes to do all the necessary work,” says University of New Mexico Institute of Meteoritics expert Horton Newsom. He conducted the work with colleagues Shawn Wright and Wolf Elston. He says that the team was amazed to learn that the rock layers are exposed directly.

This means that the team no longer needs digs in order to analyze the past events, just a lot of patience. “Such impact crater cross-sections are extremely rare in the world,” the expert says. He adds that the crater has long since been eroded entirely, but argues that additional studies of the site would help experts gain additional insights into how the impact affected the rocks underneath. The group will continue working in Santa Fe, with hopes that the actual size of the impact crater, as well as its age, will be accurately established.

Stephen Hawking: 'Humankind Belongs in Space'

2010-08-09T11:21:00.000-04:00

Technological advancements that took place over the past few decades have made the world a very dangerous place to live in. Nuclear missiles are just the tip of the iceberg when it comes to methods that humankind can employ to destroy itself. Global warming and chemical weapons are also high on the list, as are other natural factors. Famed physicist and scientist Stephen Hawking believes that the world needs to look at the stars for inspiration, and leave Earth before it's too late.

The famed expert believes that it's wrong for humankind to keep all of its eggs in a single basket, so to speak. “I believe that the long-term future of the human race must be in space. It will be difficult enough to avoid disaster on planet Earth in the next hundred years, let alone the next thousand, or million. The human race shouldn't have all its eggs in one basket, or on one planet. Let's hope we can avoid dropping the basket until we have spread the load,” Hawking tells Big Think.

He also mentions the fact that the world's resources are currently being depleted at a massively-high rate, far beyond what can be replenished naturally or artificially. Greed and the quest for profits is making large corporations hinder innovation in fields of science investigation alternative energy sources, and this will soon manifest its effects on the planet. Hawking believes that we wouldn't want to be here when that happens. Plus, he adds, the Sun will only take a few billion years before it expands to envelop Earth, so we shouldn't be here at that time.

Speaking about situations such as the Cuban Missile Crisis, which almost saw the onset of global nuclear war between the US and the Soviet Union, Hawking says that “the frequency of such occasions is likely to increase in the future. We shall need great care and judgment to negotiate them all successfully.” Even if we are successful in doing so, the Sun will kill all life on Earth over a period of time. When it begins to swell, global warming will increase its effects, until all water is evaporated. Without the precious liquid, life as we know it will disappear.

“Life on Earth will have disappeared long before 7.6 billion years. Scientists have shown that the Sun's slow expansion will cause the temperature at the surface of the Earth to rise. Oceans will evaporate, and the atmosphere will become laden with water vapor, which (like carbon dioxide) is a very effective greenhouse gas. Eventually, the oceans will boil dry and the water vapor will escape into space. In a billion years from now the Earth will be a very hot, dry and uninhabitable ball,” says Dr. Robert Smith, an astrophysicist at the University of Sussex.

How Binary Star Systems Form

2010-05-24T14:36:00.000-04:00

For many years, we have been taught to believe that most stars are similar to our Sun, in the sense that they form the sole core of their systems. This picture now appears to be dismantled piece-by-piece by new scientific evidence, which shows that a great number of cosmic fireballs are in fact members of binary systems. In these setups, two stars spin around each other, bound together by the mutual gravitational pulls they exert on each other. The mechanisms through which these binaries form have fascinated and puzzled astronomers for a long time, and now new data comes to clarify the mystery.

One of the main questions related to their development is whether the two components of the binary develop in separate molecular clouds, or if maybe they are born in the same one. Commonly, experts say that systems featuring stars that are fairly distant from each other appeared when two nearby clouds of gas and dust collapsed. When the stars orbit each other at a close distance, researchers believe that a single cloud was the source for both fireballs. But astronomers were in the dark about how a single source could produce two stars.

Experts at the University of Michigan in Ann Arbor decided to investigate the phenomenon, and used the American space agency's Spitzer Space Telescope, which surveys the sky in infrared wavelengths. Data collected with the sensitive observatory determined the existence of asymmetrical gas and dust envelopes around forming stars. These blob-like structures may promote the development of irregularities inside the clouds, which may in turn lead to the emergence of binary systems. Details of the new work appear in a recent issue of the esteemed publication Astrophysical Journal.

University of Michigan in Ann Arbor expert John Tobin, who is also the lead author of the paper, says that “we see asymmetries in the dense material around these proto-stars on scales only a few times larger than the size of the solar system. This means that the disks around them will be fed unevenly, possibly enhancing fragmentation of the disk and triggering binary star formation. We were really surprised by the prevalence of asymmetrical envelope structures. And because we know that most stars are binary, these asymmetries could be indicative of how they form,” Spitzer is managed by experts at the NASA Jet Propulsion Laboratory (JPL) in Pasadena, California.

New Evidence for Ancient Life on Mars

2010-05-24T14:35:00.000-04:00

Scientists from the NASA Johnson Space Center (JSC) recently announced that a new study they conducted on a famous Martian meteorite found in 1996 lends further credence to the fact that ancient life existed at one point on Mars. The space rock has been a cause for discord in the international scientific community since it was first discovered, and many groups have argued either for or against it containing sings of past Martian life. Using modern techniques, the JSC team determined that early life remains the most plausible explanation for the structures identified in the rocks, ScienceDaily reports.

What's interesting about this new work is that it did not focus directly on studying the ancient meteorites. Instead, the group analyzed the studies that proposed the structures found in the space rocks were not signs of life. Their results are very clear – other origins than lifeforms are not plausible for these particular samples. The investigation comes 14 years after another JSC team, led by scientists David McKay, Everett Gibson and Kathie Thomas-Keprta, published a paper in the highly-regarded journal Science, claiming the discovery of biogenic evidence in the meteorite known as ALH84001.

The recent paper, entitled “Origin of Magnetite Nanocrystals in Martian Meteorite ALH84001,” again revisits the same old hypothesis, but adds additional data to support the claims. Details of the data appear in the November issue of the journal Geochimica et Cosmochimica Acta of The Geochemical Society and The Meteoritical Society, and is authored by Thomas-Keprta. Coauthors include experts Simon Clemett, McKay, Gibson and Susan Wentworth, who are all based at the JSC Astromaterials Research and Exploration Science Directorate.

“In this study, we interpret our results to suggest that the in situ inorganic hypotheses are inconsistent with the data, and thus infer that the biogenic hypothesis is still a viable explanation,” reveals Thomas-Keprta, who was the lead author of the investigation. He is also a JSC senior scientist for Barrios Technology. “We believe that the biogenic hypothesis is stronger now than when we first proposed it 13 years ago,” adds Gibson, who is a senior scientist at the American space agency.

“The evidence supporting the possibility of past life on Mars has been slowly building up during the past decade. This evidence includes signs of past surface water including remains of rivers, lakes and possibly oceans, signs of current water near or at the surface, water-derived deposits of clay minerals and carbonates in old terrain, and the recent release of methane into the Martian atmosphere, a finding that may have several explanations, including the presence of microbial life, the main source of methane on Earth,” says McKay, who is the JSC chief scientist for exploration and astrobiology.

New Hubble pictures suggest Milky Way fell together

2010-05-05T21:17:00.001-04:00

New infrared images of the Milky Way globular cluster 47 Tucanae (this one recorded at a wavelength of 1.6 micrometers), reveal that both the cluster and the Milky Way's central bulge are 11 billion to 12 billion years old and may have formed simultaneously with the Milky Way’s halo.

BALTIMORE — A preliminary analysis of elderly stars in the Milky Way appears to strike a blow against the prevailing theory of galaxy formation. The study suggests that several large and seemingly disparate chunks of the Milky Way galaxy formed at the same time from the collapse of a single blob of gas and dust.

That’s in direct contrast to the leading galaxy-formation scenario, which holds that the Milky Way and other galaxies began small and grew bit by bit for the most part, gravitationally acquiring intergalactic gas and dust and merging with galaxies in their immediate neighborhood.

The new evidence, which astronomers emphasize is only tentative, comes from a new, ongoing study of a familiar globular cluster — a dense, elderly grouping of more than a million Milky Way stars collectively known as 47 Tucanae. Earlier this year, Harvey Richer of the University of British Columbia in Canada and his colleagues began examining 47 Tucanae with two Hubble Space Telescope cameras — the newly installed Wide Field Camera 3 and the Advanced Camera for Surveys, which stopped working early in 2007 but was revived by astronauts during the servicing mission last year.

The cluster lies near but not inside the Milky Way’s bulge, a massive concentration of stars that surrounds the galaxy’s core. But because the cluster shares several properties with the bulge, such as chemical composition and orbital motion, astronomers consider the age of 47 Tucanae a good proxy for that of the bulge.

An analysis of the Hubble portrait, which includes one of the deepest infrared views ever recorded, reveals that 47 Tucanae, and therefore the Milky Way’s bulge, formed between 11 billion and 12 billion years ago, Richer reported May 4 at a symposium on stellar evolution at the Space Telescope Science Institute in Baltimore. He said previous age estimates that did not use the new Hubble camera and put the cluster at a more youthful 9 billion years old are simply not correct.

“This is not a young cluster. That’s definitive,” Richer said. But he cautioned that both the analysis and observations of 47 Tucanae are ongoing, so the precise age determination is still “very preliminary.”

The new age determination places the bulge at roughly the same vintage as the halo of the Milky Way, a vast spherical region that extends to the outskirts of the galaxy and envelops the flattened disk containing the Milky Way’s signature spiral arms,.

Researchers had previously determined the halo’s age by studying several globular clusters that lie within it. The similarity in age of 47 Tucanae and the galactic halo suggests that the two structures may have formed simultaneously, in one giant monolithic gravitational collapse of material, Richer said. “It may have been that major components of the galaxy pretty much formed everywhere at the same time very early on and other bits and pieces came along later,” he noted.

A younger age for the bulge would have indicated that the galaxy grew more gradually and from the outside in, with the halo forming first and the central bulge arising a few billion years later.

But if the age estimate holds up, it would appear to be in conflict with the prescription for galaxy formation dictated by the cold dark matter theory, which holds that galaxies began as small fry that built themselves up by stealing gas and stars from their neighbors.

Evidence that the halo and the bulge of the Milky Way formed together could be seen either as a cosmic coincidence or a finding that suggests some previously unknown episode of violence early in the galaxy’s history, commented Rosie Wyse of Johns Hopkins University in Baltimore, who was not a collaborator on the study.

One possibility, she notes, is that the Milky Way suffered a major collision not long after its birth that drove material from the halo into the central part of the galaxy, forming the bulge. That could also explain why the mass of stars in the bulge is about 10 times heavier than that in the halo, she said.

The finding does not rule out the possibility that parts of the Milky Way grew by accreting, or gravitationally accumulating material, from neighbors, Richer said. Indeed, the Milky Way today continues to grow by pulling in small neighboring galaxies, such as the Sagittarius dwarf galaxy.

New Martian Views From Orbiting Camera Show Diversity

2010-05-05T21:13:00.000-04:00

New images from more than 750 recent observations of Mars by an orbiting telescopic camera testify to the diversity of landscapes there.

The images from the High Resolution Imaging Science Experiment camera on NASA's Mars Reconnaissance Orbiter are now available on NASA's Planetary Data System and on the camera team's website. The features visible in the images range from oddly sculpted terrain inside a giant crater to frosted dunes, deformed craters, old gullies and pits strung along fractured ground.

This new batch brings the tally from the high-resolution camera to more than 1.4 million image products derived from more than 14,200 observations. Each observation can reveal features as small as desks in areas covering several square miles.

The camera is one of six instruments on NASA's Mars Reconnaissance Orbiter, which reached Mars in 2006. For more information about the mission, see http://www.nasa.gov/mro.

First All-Sky Infrared Catalogs Released After 25 Years

2010-05-05T21:05:00.000-04:00

All-sky surveys represent one of the most important tools in astronomy today. They allow experts to set reference points for their studies, and also to compare various celestial objects between themselves, and with newly discovered ones. For the first time in more than a quarter of a century, a new series of infrared all-sky surveys, covering in excess of 1.3 million light sources, has been made available, under the name of the AKARI All-Sky Catalogs. The information is available here and here, ScienceDaily reports.

“The release of the catalogs is very timely. Many of the objects detected by AKARI and contained in these catalogs will be prime candidates for future investigation at far-infrared and submillimeter wavelengths with Herschel. These catalogs will be very useful for astronomers preparing for the next opportunity, in May, to propose observations with Herschel,” the AKARI project scientist for the European Space Agency (EAS), Alberto Salama, explains. He shares that the new datasets could be used to derive more information on subjects such as the traits of nearby stars, on how planetary systems form around new stars, or on how stars started forming very early in the history of the Universe.

Launched in February 2006, the AKARI spacecraft was Japan's first infrared astronomical satellite. Its mission ran between May 2006 and August 2007, during which time it did a full sweep of the visible sky, imaging all the targets that eventually ended up forming the catalogs. Its two main instruments were the Infrared Camera (IRC), which worked in the 9- and 18-micrometer bands, and the Far-Infrared Surveyor (FIS), which looked at the sky in the 65-, 90-, 140-, and 160-micrometer bands. IRC holds the record for most infrared sources discovered, at 70,000 objects, with FIS trailing some distance away, with only about 430,000 objects identified.

Each of the two catalogs features data from one of these two instruments. As such, rather than producing a single, large dataset, experts decided to split the information into the AKARI-IRC Point Source Catalog and the AKARI-FIS Bright Source Catalog. Behind this ambitious project was the Japanese Aerospace Exploration Agency (JAXA), which managed the AKARI mission in collaboration with ESA. Scientists from the Seoul National University, in South Korea, have also contributed to developing the satellite and its instruments. Survey-data processing took place at the ESA European Space Astronomy Center (ESAC) near Madrid, Spain.

New ESO Image Shows Thousands of Galaxies

2010-05-05T21:04:00.000-04:00

Astronomers at the European Southern Observatory (ESO) have just released a new spectacular, wide-field image of a very crowded portion of the sky. The photograph covered several thousands of very distant galaxies, according to the team behind the study, as well as a significant group of such structures that are included in the massive Abell 315 galaxy cluster. But the scientists warn that the visible portion of this particular cluster is only the tip of the iceberg. The entire structure is several times more massive, given that much of its content is made up of dark matter.

This is visible when looking at the shape of the galaxies behind it, which appear to be slightly bent. The ESO team also adds that the most of the stars we see in this new image are almost never visible from Earth with the unaided eye. Most of the bright dots we see in the evening sky are actually stars from our own galaxy, the Milky Way, plus a few extra-bright ones from neighboring galaxies such as Andromeda. Other star “collections” emit very small amounts of visible light, and are therefore too dim to be perceived by the human eye.

One interesting thing to note is that, if we were to become capable of seeing this dim light, the radiation coming from distant galaxies would basically cover the sky. Since we don't have that ability, astronomers rely on devices such as the Wide Field Imager instrument. This is located on the MPG/ESO 2.2-meter telescope facility, which is based at the ESO La Silla Observatory, high in the Chilean Andes. For the new image, scientists used three different filters and long exposure times. The composite photography that resulted from this is of both the wide-field and long-exposure kind. The WFI covered an area of the sky about 34x33 arcminutes across.

“Beginning in the center of the image and extending below and to the left, a concentration of about a hundred yellowish galaxies identifies a massive galaxy cluster, designated with the number 315 in the catalog compiled by the American astronomer George Abell in 1958. The cluster is located between the faint, red and blue galaxies and the Earth, about two billion light-years away from us. It lies in the constellation of Cetus (the Whale),” ESO scientists explain in a press release.

“The presence of dark matter is revealed through its gravitational effect: the enormous mass of a galaxy cluster acts on the light from galaxies behind the cluster like a cosmic magnifying glass, bending the trajectory of the light and thus making the galaxies appear slightly distorted. By observing and analyzing the twisted shapes of these background galaxies, astronomers can infer the total mass of the cluster responsible for the distortion, even when this mass is mostly invisible. However, this effect is usually tiny, and it is necessary to measure it over a huge number of galaxies to obtain significant results,” the astronomers add.

Deep Space as Seen by the Chandra X-Ray Observatory

2010-05-04T20:40:00.001-04:00

This new image from the Solar Dynamics Observatory's Atmospheric Imaging Assembly (AIA) shows in great detail a solar prominence taken from a March 30, 2010 eruption. The twisting motion of the material is the most noticeable feature.

(Photo: NASA/CXC/SAO)

New images from the Chandra X-ray Observatory, NASA's flagship mission for X-ray astronomy.

Read the whole article on CBSNews - Science

Mars Odyssey THEMIS images - April 26-30, 2010

2010-05-04T20:36:00.001-04:00

The following new images taken by the Thermal Emission Imaging System (THEMIS) on the Mars Odyssey spacecraft are now available:

Auqakuh Vallis (Released 26 April 2010)
This VIS image shows a small portion of Auqakuh Vallis.
Daedalia Planum (Released 27 April 2010)
Some of the youngest volcanic flows on Mars are from Arsia Mons.
Ascraeus Mons (Released 28 April 2010)
This VIS image shows part of the northeastern flank of Ascraeus Mons, one of the large Tharsis volcanoes.
Juventae Chasma (Released 29 April 2010)
Baetis Chasma is a chasmata near Valles Marineris.
Galaxias Fossae (Released 30 April 2010)
The fracture system in this VIS image is part of Galaxias Fossae, a series of fractures on the northern part of the Elysium Mons volcanic complex.

Cassini ISS images - April 26-30, 2010

2010-05-04T20:33:00.002-04:00

The following new images taken by the Imaging Science Subsystem (ISS) on the Cassini spacecraft are now available:

Hyperion's South (Released 26 April 2010)
Myriad shadows cover the pitted surface of Saturn's small moon Hyperion in this Cassini spacecraft image, which shows the moon's south pole on the right.
Woven Shadow (Released 27 April 2010)
Part of the shadow of Saturn's moon Epimetheus appears as if it has been woven through the planet's rings in this Cassini image taken about a month and a half before the planet's August 2009 equinox.
West of the Probe (Released 28 April 2010)
The Cassini spacecraft peers through Titan's atmosphere at the region called Adiri, west of the landing site of the Huygens probe on the anti-Saturn side of the moon.
Shadows from the Waves (Released 29 April 2010)
Shadows are cast by Daphnis and the moon's attendant edge waves in this Cassini spacecraft image taken about a month and a half before the Saturn's August 2009 equinox.
Crescent at Equinox (Released 30 April 2010)
The Cassini spacecraft looks down and pictures Saturn wrapped in a pencil-thin shadow of the rings just days after the planet's August 2009 equinox.

Lunar Reconnaissance Orbiter LROC and LOLA images - April 20-30, 2010

2010-05-04T20:33:00.001-04:00

The following featured images taken by the Lunar Reconnaissance Orbiter Camera (LROC) are now available:

Dante Crater Constellation Region of Interest (Released 20 April 2010)
Highlands terrain inside the Dante Crater Constellation Site.
Craters on the Schrodinger pyroclastic cone (Released 22 April 2010)
LROC NAC closeup clustered craters on the Schrodinger pyroclastic cone, one of the NASA Constellation regions of interest.
Constellation Region of Interest at Mare Tranquillitatis (Released 27 April 2010)
Close up of a northwest trending wrinkle ridge in the high-Ti basaltic lava plains of Mare Tranquillitatis, near a Constellation region of interest.
Floor of Tsiolkovskiy - Constellation Region of Interest (Released 30 April 2010)
LROC NAC view of boulders on an outlying rampart of the complex central peak of Tsiolkovskiy crater within the Constellation region of interest.

Lunar Orbiter Laser Altimeter (LOLA) Image of the Week:

Copernicus (Released 30 April 2010)
800 million years ago an impactor struck the eastern extent of Oceanus Procellarum, the "Ocean of Storms."

Sand Flows May Have Created Martian Gullies

2010-05-04T20:30:00.001-04:00

Martian gullies may have been formed through the action of fluid sand, and not liquid water, a new research shows

For the past 11 years, ever since the Mars Global Surveyor spacecraft sent back images of the mid-latitude regions of the Red Planet, astronomers have been obsessed with the gully-like features they noticed in the datasets. The landscape features resembled their Earth-based counterparts significantly, and so experts naturally assumed that the formation process must be the same between the two. But a new study now seems to suggest that this is not the case, and that water is not responsible for the gullies on our neighboring planet, Technology Review reports.

Over time, various theories have argued that the gullies were not in fact formed by water, but by the flow of sand on the surface. Now, a series of experiments appears to validate this assumption and indeed verify that sand flows are responsible for carving out the landscape features. An additional element that seems to support this idea is the vast amount of data sent back by Spirit and Opportunity, the NASA rovers that are currently in their seven year on the planet.

While the new theory does nothing in the way of proposing that water never existed on Mars, it simply draws attention to a number of issues related to the age of the gullies. While the two exploration rovers indeed found signs of water on the Red Planet, the liquid was present at their respective locations billions of years ago, and not sooner. On the other hand, the gullies were found to be only a few million years old. This clearly eliminates the possibility that they were created by water. Some proposed that water from aquifers may be responsible, but the idea does not stand because rain is needed to replenish aquifers, and no such thing exists on Mars.

Scientists at the Universidad Nacional Autonoma de Mexico, led by experts Yolanda Cedillo-Flores and Hector Javier Durand-Manterola, propose a new explanation for the gullies. They say that the formations developed as frozen carbon dioxide in the ground started to sublimate into the Martian atmosphere. This process in turn makes the sand become “fluid,” and start “flowing” even above light slopes. This explanation also accounts for why no gullies exist at the equator or poles. Carbon dioxide cannot freeze at the equator, and cannot unfreeze at the poles, the experts say.

Cassini Returning Enceladus Gravity Data

2010-05-04T20:27:00.000-04:00

NASA's Cassini spacecraft successfully completed its 26-hour gravity observation at Saturn's moon Enceladus this week, sending back data scientists will use to understand the moon's interior composition and structure.

The flyby took Cassini through the water-rich plume flaring out from Enceladus' south polar region, with a closest approach of about 100 kilometers (60 miles) occurring in the late afternoon of April 27, 2010, Pacific Time, or just after midnight April 28 UTC.

A steady radio link to NASA's Deep Space Network on Earth enabled Cassini's scientists to use the radio science instrument to measure the variations in the gravitational pull of Enceladus. Analyzing the wiggles will help scientists understand whether an ocean, pond or great lake lies under the famous "tiger stripe" fractures that spew water vapor and organic particles from the south polar region.

Results from the experiment will also tell scientists if bubbles of warmer ice in the interior rise toward that region's surface like an underground lava lamp.

Radio science was prime during the flyby and controlled spacecraft pointing. The optical instruments were not pointed at Enceladus during most of the flyby, so the imaging camera obtained some more distant pictures.

Cassini often relies on thrusters to control attitude during flybys such as this one, but this time it turned the thrusters off and relied on its reaction wheels. Using thrusters adds acceleration effects to the spacecraft, complicating the precise measurements needed for the radio science experiment.

Largest Atlas Of Nuclear Galactic Rings Unveiled

2010-05-04T20:26:00.000-04:00

An international team of astrophysicists has just unveiled the most complete atlas of nuclear rings, enormous star-forming ring-shaped regions that circle certain galactic nuclei. The catalogue, published in the Monthly Notices of the Royal Astronomical Society, includes 113 such rings in 107 galaxies.

"AINUR (the Atlas of Images of Nuclear Rings) is the most complete atlas of nuclear rings created to date", Sebastien Comeron, a researcher at the Institute of Astrophysics of the Canary Islands (IAC), and co-author of the joint study with other scientists from the universities of La Laguna, Oulu (Finland) and Alabama (United States), tells SINC.

The atlas has just been published in the journal Monthly Notices of the Royal Astronomical Society, and covers 113 nuclear rings in 107 different galaxies. Six are dust rings in elliptical galaxies, while the rest (the majority) are star-forming rings in disc galaxies.

The nuclear rings are ring-shaped, star-forming configurations located around galactic nuclei. They range in size on average from between 500 to 3,000 light years, and they are very bright because they contain an abundance of young stars, including some extremely massive ones. This kind of star has a short lifetime but shines very brightly before exploding as a supernova.

To find the rings, the astrophysicists used images from around 500 galaxies observed by the Hubble space telescope, which belongs to NASA and the European Space Agency, as well as using other references. The images were processed using filters, generating various kinds of maps to help identify the rings more easily.

Rings and Lindblad resonances
"The AINUR atlas has also looked for relationships between the properties of the nuclear rings and those of the galaxies in which they are found", says Comeron, "and we have been able to statistically prove that most rings are associated with Lindblad resonances (gravitational shoves that push objects out of certain orbits and into others)".

The astrophysicists have shown that when the rings are in a barred galaxy (within disc galaxies, which have a central cylinder or 'cigar' of stars), the maximum radius that a nuclear ring can attain is 25% of the length of the bar, and that the maximum radius is inversely proportional to the strength of the bar.

This is the behaviour that was predicted for the internal Lindblad resonances, which are determined by the size of the bar and their strength (how elliptical this is). If the bar is small or very elliptical, the resonance orbit becomes small, but if it is large or not very elliptical, the orbits become bigger.

The researchers also found that, contrary to what had been believed until now, a significant proportion of nuclear rings are to be found in non-barred galaxies (around 20%). The resonances needed to form the rings in these galaxies "are probably created by strong spiral arms, weak oval distortions of the disc and some lesser interaction with neighbouring galaxies", the scientists say.

CSIRO Telescope Spots Mega-Star Cradle

2010-05-04T20:24:00.000-04:00

Mid-infrared image of BYF 73 from NASA's Spitzer Space Telescope. The yellowish wisps to the right are remnants of gas that have been heated and are being driven off by the massive young stars within them (seen in blue). The large-scale collapse of colder gas to form a massive cluster is centred around the bright stars just to the left of the heated wisps. Image credit - NASA/JPL-Caltech

Using a CSIRO radio telescope, an international team of researchers has caught an enormous cloud of cosmic gas and dust in the process of collapsing in on itself - a discovery which could help solve one of astronomy's enduring conundrums: 'How do massive stars form?'

Dr Peter Barnes from the University of Florida says astronomers have a good grasp of how stars such as our Sun form from clouds of gas and dust, but for heavier stars - ten times the mass of the Sun or more - they are still largely in the dark, despite years of work.

"Astronomers are still debating the physical processes that can generate these big stars," Dr Barnes says.

"Massive stars are rare, making up only a few per cent of all stars, and they will only form in significant numbers when really massive clouds of gas collapse, creating hundreds of stars of different masses. Smaller gas clouds are not likely to make big stars."

Accordingly, regions in space where massive stars seem to be forming are also rare. Most are well over 1000 light-years away, making them hard to observe.

Using CSIRO's 'Mopra' radio telescope - a 22m dish near Coonabarabran, NSW - the research team discovered a massive cloud of mostly hydrogen gas and dust, three or more light-years across, that is collapsing in on itself and will probably form a huge cluster of stars.

Dr Stuart Ryder of the Anglo-Australian Observatory said the discovery was made during a survey of more than 200 gas clouds.

"With clouds like this we can test theories of massive star cluster formation in great detail."

The gas cloud, called BYF73, is about 8,000 light years away, in the constellation of Carina ("the keel") in the Southern sky.

Evidence for 'infalling' gas came from the radio telescope's detection of two kinds of molecules in the cloud - HCO+ and H13CO+. The spectral lines from the HCO+ molecules in particular showed the gas had a velocity and temperature pattern that indicated collapse.

Mopra Research Scientist at CSIRO Astronomy and Space Science, Dr Kate Brooks, said the Mopra telescope excels at giving a picture of the complex chemistry of cosmic gas clouds.

"Much of its time is used for large projects like this, and almost all Mopra projects are international collaborations."

The CSIRO telescope observations were confirmed by observations with the Atacama Submillimeter Telescope Experiment (ATSE) telescope in Chile.

The research team calculates that the gas is falling in at the rate of about three per cent of the Sun's mass every year - one of the highest rates known.

Follow-up infrared observations made with the 3.9-m Anglo-Australian Telescope (also near Coonabarabran, NSW) showed signs of massive young stars that have already formed right at the centre of the gas clump, and new stars forming.

Star-formation in the cloud was also evident in archival data from the Spitzer and MSX spacecraft, which observe in the mid-infrared.

Gas cloud BYF73 was found during a large-scale search for massive star-forming regions - the Census of High- and Medium-mass Protostars, or CHaMP. This is one of the largest, most uniform and least biased surveys to date of massive star-forming regions in our Galaxy.

NASA To Probe First Moments Of The Universe

2010-04-29T22:02:00.001-04:00

This graphic shows the universe as it evolved from the big bang to now. Goddard scientists believe that the universe expanded from subatomic scales to the astronomical in a fraction of a second after its birth. They now building, along with their university partner, an instrument that searches for clues that the inflation did, in fact, occur. Credit: NASA/WMAP Science Team

Sophisticated new technologies created by NASA and university scientists are enabling them to build an instrument designed to probe the first moments of the universe's existence.

Former NASA scientist Chuck Bennett, now an astrophysicist at Johns Hopkins University (JHU) in Baltimore, Md., won a $5-million National Science Foundation grant to build a new ground-based instrument, the Cosmology Large Angular Scale Surveyor (CLASS). Bennett is building CLASS with his collaborators at the NASA Goddard Space Flight Center in Greenbelt, Md.

Goddard will provide most of the instrument's sophisticated detectors and other state-of-the-art technologies that will allow the scientists to test the "inflation theory" of the universe's origin.

Staggering Idea
Considered a staggering idea just 30 years ago, the inflation theory postulates that the universe expanded far faster than the speed of light and grew exponentially almost instantaneously after the big bang, the moment the universe sprang into existence 13.7 billion years ago.

In particular, the telescope will search for a unique polarization pattern in the cosmic background radiation - the remnant light from the first moment of the universe's creation that bathes the sky in all directions. Because of the size and expansion of the universe, scientists can study this ancient light only if their instruments are tuned to microwave frequencies.

If the cosmic growth spurt from inflation really happened, scientists say the event could have created gravitational waves, which are ripples in the fabric of space. The theory also predicts that these gravitational waves would have caused the background light to be polarized in a particular pattern. The telescope, therefore, will look for this signature pattern.

"Miraculously enough, it is within our ability to probe back into the first moments of the universe and learn what happened then," Bennett said.

The CLASS team, which also includes other partner institutions, will complete the instrument in 2014, equipping it with detectors sensitive to microwave light. The team then will ship the instrument to the Atacama Desert in northern Chile where it will observe large swaths of the microwave sky in search of the polarized signature.

Tantalizing Clues
Although scientists have yet to find the polarization pattern, they have uncovered tantalizing clues that inflation did, in fact, happen. Scientific results from the Goddard-developed Cosmic Background Explorer (COBE) found tiny temperature differences in the cosmic background radiation. These differences varied by only a few millionths of a degree and pointed to density differences that eventually gave rise to the stars and galaxies seen today.

COBE's successor, the Goddard-led Wilkinson Microwave Anisotropy Probe (WMAP), examined the tiny temperature differences in more detail and discovered new evidence for inflation. Among other things, WMAP showed that the geometry of the universe is close to flat - a physical dimension attributable to inflation. However, other theories explain these dynamics. What the scientific community needs is definitive proof of the primordial gravity waves - phenomena that could have been produced only by inflation.

Another Goddard Mission Complements CLASS
CLASS is not the only effort aimed at finding the same telltale evidence. Another Goddard team is now building a balloon-based instrument, the Primordial Inflation Polarization Exploration (PIPER) that Principal Investigator Al Kogut hopes to launch in 2012. "CLASS and PIPER are perfect partners," said Goddard scientist Ed Wollack, who is involved in the CLASS project. "They share many technologies while spanning a wide frequency range. They will do great science while demonstrating the technologies for a space mission."

Although both CLASS and PIPER are looking for the same polarization signature, they will approach the challenge using different detector technologies to study different microwave frequencies. Both detector technologies were developed at Goddard.

"The more frequencies you study, the better your chance of detecting the pattern of inflation," said David Chuss, a Goddard scientist working on CLASS.

The ultimate goal for the Goddard-JHU team is leveraging its expertise with CLASS and PIPER and winning a possible follow-on space observatory that would examine the primordial background light with even greater precision. "What we're doing is very much what we need to do to be competitive for an observatory if NASA decides to launch one," Chuss said.

Radar Clicks Asteroid Pic

2010-04-29T22:00:00.001-04:00

Radar image of asteroid 2005 YU55. Image credit: NASA/Cornell/Arecibo

Near-Earth asteroid 2005 YU55 was "imaged" by the Arecibo Radar Telescope in Puerto Rico on April 19. Data collected during Arecibo's observation of 2005 YU55 allowed the Near-Earth Object Program Office at NASA's Jet Propulsion Laboratory to refine the space rock's orbit, allowing scientists to rule out any possibility of an Earth impact for the next 100 years.

The space rock was about 2.3 million kilometers (1.5 million miles) from Earth at the time this image of the radar echo was generated. The ghostly image has a resolution of 7.5 meters (25 feet) per pixel. It reveals 2005 YU55 as a spherical object about 400 meters (1,300 feet) in size.

Not only can the radar provide data on an asteroid's dimensions, but also on its exact location in space. Using Arecibo's high-precision radar astrometry capability, scientists were able to reduce orbit uncertainties for YU55 by 50 percent.

"At one time we had classified 2005 YU55 as a potential threat," said Steve Chesley, a scientist at JPL's Near-Earth Object Program Office.

"Prior to the Arecibo radar passes on April 19 thru 21, we had eliminated almost all upcoming Earth flybys as possibilities of impact. But there were a few that had a low remaining probability of impact.

"After incorporating the data from Arecibo, we were able to rule impacts out entirely for the next 100 years."

With more observations in the coming years, scientists may be able to accurately plot 2005 YU55's orbit even further out.

NASA detects, tracks and characterizes asteroids and comets passing close to Earth using both ground- and space-based telescopes.

The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them, and plots their orbits to determine if any could be potentially hazardous to our planet.

The Search for Extraterrestrials Narrows

2010-04-29T21:54:00.001-04:00

A large number of experts participated recently at the Astrobiology Science Conference, which was held near Houston, Texas. At the meeting, scientists and NASA representatives spoke about the challenges still ahead in discovering forms of life on other planet, both in our solar system and beyond. The participants also addressed the controversy that famed physicists Stephen Hawking set in motion recently, when he said that Earth may be better off not searching for signs of extraterrestrial intelligence.

According to prominent scientists, the best possible places to look for alien life are currently in the process of being pinned down, and addressed in future space missions. The conference was held to mark the 50th anniversary of the quest for life in other places in the Universe. On Wednesday, NASA experts said that the American space agency was at the time considering a number of no less than 28 future space missions, all of which will be aimed at discovering alien life.

“We're interested and prepared to discover any form of life,” explained during a teleconference NASA Headquarters senior astrobiology scientist Mary Voytek. “Astrobiology and the search for life is really central to what we should be doing next in the exploration of the solar system,” added Steve Squyres, who is a planetary scientists at the Cornell University, in Ithaca, New York. The expert is also the principal science investigator of the Mars Exploration Rovers project, which manages the twin geology robots Spirit and Opportunity.

He mentioned that potential targets for astrobiology research could include the Red Planet, Mercury, as well as numerous moons of gas giants such as Jupiter and Saturn, such as Titan, Enceladus and Europa. According to Squyres, a sample-return mission to Mars would prove “invaluable” for this field of research, and would contribute to advancing our knowledge of how the planet looked like before it became the cold, desolate wasteland it is today.

“I personally think if we're ever going to be able to show that there was past life on Mars – if there was past life on Mars – I think we're going to need to study the samples here on Earth rather than [with robots]. I think if we had the rocks back tomorrow and I had them in my lab, I think we could solve this problem,” added University of California in Los Angeles (UCLA) research scientist Bill Schopf, quoted by Space.

Winter Solstice Just Three Weeks Away For Spirit

2010-04-28T22:15:00.000-04:00

Spirit remains silent at her location called "Troy" on the west side of Home Plate. No communication has been received from the rover since Sol 2210 (March 22, 2010).

It is likely that Spirit has experienced a low-power fault and has powered off all sub-systems, except her master clock. The rover will use the available solar array energy to recharge her batteries.

When the batteries recover to a sufficient state of charge, Spirit will wake up and begin to communicate. When that does happen, Spirit will also trip an up-loss timer fault.

This fault response will allow the rover to communicate over Ultra-High Frequency (UHF) as well as X-band.

It is not know when the rover will wake up, so the project has been listening for any X-band signal from Spirit through the Deep Space Network every day.

The relay orbiters are also listening over any scheduled UHF relay passes. The winter solstice is just three weeks away (Sol 2261, or May 13, 2010).

Total odometry is unchanged at 7,730.50 meters (4.80 miles).

Webb Telescope Passes Mission Design Review Milestone

2010-04-28T22:13:00.001-04:00

NASA's Northrop Grumman-built James Webb Space Telescope has passed its most significant mission milestone to date, the Mission Critical Design Review, or MCDR. This signifies the integrated observatory will meet all science and engineering requirements for its mission.

"I'm delighted by this news and proud of the Webb program's great technical achievements," said Eric Smith, Webb telescope program scientist at NASA Headquarters in Washington.

"The independent team conducting the review confirmed the designs, hardware and test plans for Webb will deliver the fantastic capabilities always envisioned for NASA's next major space observatory. The scientific successor to Hubble is making great progress."

NASA's Goddard Space Flight Center, in Greenbelt, Md., manages the mission. Northrop Grumman, Redondo Beach, Calif., is leading the design and development effort.

"This program landmark is the capstone of seven years of intense, focused effort on the part of NASA, Northrop Grumman and our program team members," said David DiCarlo, sector vice president and general manager of Northrop Grumman Space Systems.

"We have always had high confidence that our observatory design would meet the goals of this pioneering science mission. This achievement testifies to that, as well as to our close working partnership with NASA."

The MCDR encompassed all previous design reviews including the Integrated Science Instrument Module review in March 2009; the Optical Telescope Element review completed in October 2009; and the Sunshield review completed in January 2010. The project schedule will undergo a review during the next few months.

The spacecraft design, which passed a preliminary review in 2009, will continue toward final approval next year.

The review also brought together multiple modeling and analysis tools. Because the observatory is too large for validation by actual testing, complex models of how it will behave during launch and in space environments are being integrated. The models are compared with prior test and review results from the observatory's components.

Although the MCDR approved the telescope design and gave the official go-ahead for manufacturing, hardware development on the mirror segments has been in progress for several years.

Eighteen primary mirror segments are in the process of cryo-polishing and testing at Ball Aerospace in Huntsville, Ala. Manufacturing on the backplane, the structure that supports the mirror segments, is well underway at Alliant Techsystems, or ATK, in Magna, Utah.

This month ITT Corp. in Rochester, N.Y., demonstrated robotic mirror installation equipment designed to position segments on the backplane. The segments' position will be fine-tuned to tolerances of a fraction of the width of a human hair. The telescope's sunshield moved into its fabrication and testing phase earlier this year.

The three major elements of Webb - the Integrated Science Instrument Module, Optical Telescope Element and the spacecraft itself - will proceed through hardware production, assembly and testing prior to delivery for observatory integration and testing scheduled to begin in 2012.

The Webb is the premier next-generation space observatory for exploring deep space phenomena from distant galaxies to nearby planets and stars.

The telescope will provide clues about the formation of the universe and the evolution of our own solar system, from the first light after the Big Bang to the formation of star systems capable of supporting life on planets like Earth. The telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency.

Changes To Last Two Planned Shuttle Launches

2010-04-28T22:09:00.001-04:00

NASA is planning to make some changes to the target launch dates for the last two scheduled space shuttle flights. Scientists with the Alpha Magnetic Spectrometer, or AMS, program recently decided to change out the current magnet in the particle physics experiment module that will be attached to the International Space Station to a longer lasting one.

This will take advantage of NASA's plan to extend station operations until at least 2020.

Because of the magnet change, space shuttle Endeavour's STS-134 mission, which will carry the AMS experiment to the station and was targeted to launch July 29, now is expected to launch no earlier than mid-November 2010. An exact target launch date hasn't yet been determined.

The AMS is designed to help study the formation of the universe and search for evidence of dark matter and antimatter by measuring cosmic rays.

Space shuttle Discovery's STS-133 mission currently remains targeted for its Sept. 16 launch date, but managers will continue to assess its readiness for flight and make changes as appropriate.

Space Shuttle Program managers are meeting at NASA's Kennedy Space Center in Florida for a Flight Readiness Review, or FRR, for space shuttle Atlantis' upcoming STS-132 mission.

The agency-level FRR is scheduled for May 5. During the 12-day mission, Atlantis and six astronauts will deliver an Integrated Cargo Carrier and a Russian-built Mini Research Module to the International Space Station.

At NASA's Johnson Space Center in Houston, the flight crew is taking part in an integrated ascent simulation.

Liftoff is targeted for May 14 at 2:20 p.m. EDT.

SDO Observes Massive Eruption And Scorching Rain

2010-04-28T22:07:00.000-04:00

Just last week, scientists working with NASA's new Solar Dynamics Observatory (SDO) released the most astonishing movies of the sun anyone had ever seen. Now, they're doing it again.

"SDO has just observed a massive eruption on the sun-one of the biggest in years," says Lika Guhathakurta of NASA headquarters in Washington DC. "The footage is not only dramatic, but also could solve a longstanding mystery of solar physics."

Karel Schrijver of Lockheed Martin's Solar and Astrophysics Lab is leading the analysis. "We can see a billion tons of magnetized plasma blasting into space while debris from the explosion falls back onto the sun surface. These may be our best data yet."

The movie, recorded on April 19th, spans four hours of actual time and more than 100,000 km of linear space. "It's huge," says Schrijver. Indeed, the entire planet Earth could fit between the plasma streamers with room to spare.

Astronomers have seen eruptions like this before, but rarely so large and never in such fluid detail. As science team member Alan Title of Lockheed Martin pointed out at last week's press conference, "no other telescope comes close to the combined spatial, temporal and spectral resolution of SDO."

Schrijver says his favorite part of the movie is the coronal rain. "Blobs of plasma are falling back to the surface of the sun, making bright splashes where they hit," he explains. "This is a phenomenon I've been studying for years."

Coronal rain has long been a mystery. It's not surprising that plasma should fall back to the sun. After all, the sun's gravity is powerful. The puzzle of coronal rain is how slowly it seems to fall. "The sun's gravity should be pulling the material down much faster than it actually moves. What's slowing the descent?" he wonders.

For the first time, SDO provides an answer.

"The rain appears to be buoyed by a 'cushion' of hot gas," says Schrijver. "Previous observatories couldn't see it, but it is there."

One of SDO's game-changing capabilities is temperature sensing. Using an array of ultraviolet telescopes called the Atmospheric Imaging Assembly (AIA), the observatory can remotely measure the temperature of gas in the sun's atmosphere. Coronal rain turns out to be relatively cool-"only" 60,000 K. When the rains falls, it is supported, in part, by an underlying cushion of much hotter material, between 1,000,000 and 2,200,000 K.

"You can see the hot gas in the color-coded temperature movie," says Schrijver. "Cool material is red, hotter material is blue-green. The hot gas effectively slows the descent of the coronal rain."

Dick Fisher, the head of NASA's Heliophysics Division in Washington DC, has been working in solar physics for nearly forty years. "In all that time," he says, "I've never seen images like this."

"I wonder, what will next week bring?"

Japan to launch 'space yacht' propelled by solar particles

2010-04-28T22:05:00.000-04:00

Japan is to launch a "space yacht" propelled by solar particles that bounce off its kite-shaped sails, the country's space agency said Tuesday.

A rocket carrying the Ikaros -- an acronym for Interplanetary Kite-craft Accelerated by Radiation of the Sun -- will blast off from the Tanegashima space centre in southern Japan on May 18.

"Ikaros is a 'space yacht' that gets propulsion from the pressure of sunlight particles bouncing off its sail," Yuichi Tsuda, space systems expert at the Japan Aerospace Exploration Agency (JAXA), told journalists.

The flexible sails, which are thinner than a human hair, are also equipped with thin-film solar cells to generate electricity to create "a hybrid technology of electricity and pressure", Tsuda said.

"Solar sails are the technology that realises space travel without fuel as long as we have sunlight. The availability of electricity would enable us to navigate farther and more effectively in the solar system."

Ikaros, which has cost 1.5 billion yen (16 million dollars) to develop, will be the first use of the technology in deep space, as past experiments have been limited to unfolding its sails in orbits around the Earth, said Tsuda.

JAXA plans to control the path of Ikaros by changing the angle at which sunlight particles bounce off the silver-coloured sail.

Ikaros will be a short cylindrical shape when it is released into space and will then extend its 14-metre (46 foot) sail, JAXA said.

The name of the spacecraft alludes to Icarus, the figure from Greek mythology who flew too close to the sun and fell into the sea, but Tsuda promised that "this Ikaros will not fly into the sun".

The same rocket will also launch Japan's first satellite bound for Venus, called the Akatsuki, or PLANET-C, which will work closely with Venus Express, a satellite sent earlier by the European Space Agency.

In coming years, JAXA may launch other bold projects.

An expert panel to the government has proposed Japan send a wheeled robot to the moon in five years and build the world's first lunar base by 2020, a Strategic Headquarters for Space Policy official said Tuesday.

Under the plan, the robot's tasks would include setting up an observation device, gathering geological samples and sending data back to Earth. The robot would also set up solar panels to generate energy, the official said.

The expert panel initially considered sending a two-legged humanoid but judged a "rover-type" robot more practical. "It is still difficult for a biped robot to walk on a bumpy surface, even on Earth," the official said.

The team also envisions building the world's first station on the moon by about 2020, which would be staffed by advanced wheeled robots, he said.

The group estimates the unmanned mission would cost Japan 200 billion yen (two billion dollars) over the next 10 years.

The 20-member team -- made up of experts from JAXA as well as business and academia -- advises Transport Minister Seiji Maehara.

It plans to submit a report to Maehara, the minister in charge of space exploration, by late June, which would be discussed at the Strategic Headquarters for Space Policy, chaired by Prime Minister Yukio Hatoyama.

Asteroid Ice May Be Living Fossil With Clues To Oceans' Origins

2010-04-28T22:04:00.001-04:00

The first-ever discovery of ice and organic molecules on an asteroid may hold clues to the origins of Earth's oceans and life 4 billion years ago.

University of Central Florida researchers detected a thin layer of water ice and organic molecules on the surface of 24 Themis, the largest in a family of asteroids orbiting between Mars and Jupiter.

Their unexpected findings will be published in Nature, which will featuretwo complementary articles by the UCF-led team and by another team of planetary scientists.

"What we've found suggests that an asteroid like this one may have hit Earth and brought our planet its water," said UCF Physics Professor HumbertoCampins, the study's lead author.

Some theories suggest asteroids brought water to Earth after the planet formed dry. Scientists say the salts and water that have been found in some meteorites support this view.

Using NASA's Infrared Telescope Facility in Hawaii, Campins and his team of researchers measured the intensity of the reflected sunlight as 24 Themis rotated. Differences in intensity at different wavelengths helped researchers determine the makeup of the asteroid's surface.

Researchers were surprised to find ice and carbon-based compounds evenly distributed on 24 Themis. More specifically, the discovery of ice is unexpected because surface ice should be short lived on asteroids, which are expected to be too warm for ice to survive for long.

The distance between this asteroid and the sun is about three times greater than between Earth and the sun.

Researchers will continue testing various hypotheses to explain the presence of ice. Perhaps most promising is the possibility that 24 Themis might have preserved the ice in its subsoil, just below the surface, as a kind of "living fossil" or remnant of an early solar system that was generally considered to have disappeared long ago.

Scientists Finds Evidence Of Water Ice On Asteroid's Surface

2010-04-28T22:02:00.000-04:00

This image shows the Themis Main Belt which sits between Mars and Jupiter. Asteroid 24 Themis, one of the largest Main Belt asteroids, was examined by University of Tennessee scientist, Josh Emery, who found water ice and organic material on the asteroid's surface. His findings were published in the April 2010 issue of Nature. Credit: Josh Emery/University of Tennessee, Knoxville

Asteroids may not be the dark, dry, lifeless chunks of rock scientists have long thought.

Josh Emery, research assistant professor with the earth and planetary sciences department at the University of Tennessee, Knoxville, has found evidence of water ice and organic material on the asteroid 24 Themis. This evidence supports the idea that asteroids could be responsible for bringing water and organic material to Earth.

The findings are detailed in the journal "Nature."

Using NASA's Infrared Telescope Facility on Hawaii's Mauna Kea, Emery and Andrew Rivkin of Johns Hopkins University in Laurel, Md., examined the surface of 24 Themis, a 200-kilometer wide asteroid that sits halfway between Mars and Jupiter.

By measuring the spectrum of infrared sunlight reflected by the object, the researchers found the spectrum consistent with frozen water and determined that 24 Themis is coated with a thin film of ice. They also detected organic material.

"The organics we detected appear to be complex, long-chained molecules. Raining down on a barren Earth in meteorites, these could have given a big kick-start to the development of life," Emery said.

Emery noted that finding ice on the surface of 24 Themis was a surprise because the surface is too warm for ice to stick around for a long time.

"This implies that ice is quite abundant in the interior of 24 Themis and perhaps many other asteroids. This ice on asteroids may be the answer to the puzzle of where Earth's water came from," he said.

Still, how the water ice got there is unclear.

24 Themis' proximity to the sun causes ice to vaporize. However, the researchers' findings suggest the asteroid's lifetime of ice ranges from thousands to millions of years depending on the latitude.

Therefore, the ice is regularly being replenished. The scientists theorize this is done by a process of "outgassing" in which ice buried within the asteroid escapes slowly as vapor migrates through cracks to the surface or as vapor escapes quickly and sporadically when 24 Themis is hit by space debris.

Since Themis is part of an asteroid "family" that was formed from a large impact and the subsequent fragmentation of a larger body long ago, this scenario means the parent body also had ice and has deep implications for how our solar system formed.

The discovery of abundant ice on 24 Themis demonstrates that water is much more common in the Main Belt of asteroids than previously thought.

"Asteroids have generally been viewed as being very dry. It now appears that when the asteroids and planets were first forming in the very early Solar System, ice extended far into the Main Belt region," Emery said.

"Extending this refined view to planetary systems around other stars, the building blocks of life - water and organics - may be more common near each star's habitable zone. The coming years will be truly exciting as astronomers search to discover whether these building blocks of life have worked their magic there as well."

The scientists' discovery also further blurs the line between comets and asteroids. Asteroids have long been considered to be rocky and comets icy. Furthermore, it was once believed that comets could have brought water to Earth. This theory was nixed when it was discovered comets' water has different isotopic signatures than water on Earth.

Now, due to Emery and Rivkin's findings, many wonder if asteroids could be responsible for seeding Earth with the ingredients for life.

First Serious Study Looks for the Sun's 'Brothers'

2010-04-28T22:00:00.000-04:00

Like all other stars before it, and all those that will come after it, the Sun was born in a nebula, surrounded by thick, massive clouds of cosmic dust and hydrogen gas. It first ignited some 5 billion years ago, alongside tens to thousands of other stars, all of which must be of similar age and chemical makeup. Now, in the first-ever complex study on the issue, astronomers begin looking for the Sun's siblings, in a research that could ultimately provide us with more clues as to how the solar system evolved over time, Technology Review reports.

Finding the birthplace of our star could also assist astronomers in answering fundamental questions about the origin of the solar system, in addition to providing information as to which direction the Sun has been traveling in for the past 5 billion years, when reported to the center of the Milky Way. This knowledge could then better inform us in understanding the conditions that eventually led to the appearance of life on Earth billions of years ago. Mysteries related to sudden changes in the planet's climate could also be revealed by studying stars formed from the same nebula as the Sun.

When compared with other yellow dwarfs, as well as with other objects in this part of the Milky Way, the Sun exhibits an unusually-high concentration of metallic elements. This abnormality has puzzled astronomers for many years, and it's now believed that identifying the star's birthplace could help unravel this enigma as well. For all these reasons, researchers at the Missouri State University, led by expert Anthony Brown, conducted the first serious astronomical search for the stars that appeared at the same time our own celestial fireball did. Unfortunately, the results are not encouraging.

The main issue plaguing such an effort is the magnitude of the needed search. Recent data on how nebulae function reveal that some stars may be ejected from within their nurseries as if sprayed from a cosmic hose. This means that their formation process is very chaotic, and also implies that our star's siblings may be spread apart over distances exceeding 3,000 light-years. Covering such vast distances is like looking for a needle in a haystack, given that the area contains an estimated 100 million stars. Of these objects, astronomers have accurate information on just 100,000 of them, which is a small portion of our solar system's neighborhood.

There is no reason to disappoint, however. Though a Sun sibling has not been found within 100 parsecs from our star, astronomers take comfort in the fact that the year 2012 will see the launch of the Gaia spacecraft. The instrument will be the successor of the Hipparcos space probe, which is responsible for providing experts with most data on the 100,000 stars analyzed until now. Gaia will conduct the first decent-quality 3D investigation of the Milky Way, and will map more than 1 billion stars. However, we will have to wait until 2020 for this census to be done.

GOES-15 Snaps First Infrared Images

2010-04-28T21:58:00.001-04:00

NOAA's newest Geostationary Operational Environmental Satellite (GOES-15) took its first Imager full-disk infrared image of the Earth on April 26

Experts at NASA and the US National Oceanic and Atmospheric Administration (NOAA) announce that their newest orbital satellite has finally opened its infrared “eyes” a couple of days ago. The group says that the Geostationary Operational Environmental Satellite (GOES-15) took the first images of our planet in these wavelengths from its vantage point, some 22,236 miles above the surface, on April 26.

The infrared equipment on GOES-15 is of tremendous practical importance, especially to meteorologists and weather forecasters. Observing the planet in these wavelengths enables these experts to gain more data on temperatures on the ground, in the sea and in the air, as well as to derive various other data. For example, they can calculate wind, temperature and moisture profiles for the atmosphere, and can observe how smoke plumes – such as those from volcanic eruptions – migrate across the surface of the planet. The IR instruments can also be used to monitor wildfires, experts add.

“This (image) marks the final stage of the critical events for the spacecraft and indicates that the visible and infrared spacecraft imaging instruments are performing as expected. We’re looking forward to more imagery as we finish up post-launch testing,” explains the NASA GOES deputy project manager, Andre Dress. The expert is based at the space agency's Goddard Space Flight Center (GSFC), in Greenbelt, Maryland. The new picture was snapped using the multi-channel GOES Imager instrument, Space Fellowship reports.

Another instrument that can produce advanced-quality infrared data is the GOES Sounder. Using datasets this payload collects, mathematicians can apply analysis technique to determine surface and cloud-top temperatures, as well as ozone distribution, temperature and moisture profile across the planet's atmosphere. The first infrared information came from GOES less than three weeks after the satellite relayed its first visible-light images of Earth, on April 6. The space craft was launched on March 4 this year, from the Cape Canaveral Air Force Station (CCAFS) Space Launch Complex 37, in Florida.

NOAA and NASA began verifications of GOES-15's systems on March 24. The procedures will last for about 150 days, after which time NASA will hand over operational control of the spacecraft to NOAA.

Creating a 'Perpetual Eclipse' in Space

2010-04-28T21:56:00.000-04:00

StarTiger-2 external coronagraph demonstrator during testing

In September 2009, a group of prominent scientists was convened by the European Space Agency (ESA) at one of its research facilities with a single objective – produce a space-based setup that would allow for the continuous analysis of a portion of the Sun hiding in plain sight. The results of the investigation were announced yesterday, April 27, as the six-month-long research project was officially closed down on time, at the agency's European Space Research and Technology Center (ESTEC), in the Netherlands.

The StarTiger project is one of ESA's latest endeavors, and it was developed at the Laboratoire Astrophysique d’Marseille (LAM), where the science team was convened. Inside a clean room at the facility, the researchers constructed a scale-model prototype of the new mission, whose main goal is to create a perpetual eclipse in space. Usually, the edges of the Sun are only visible from Earth during a full eclipse by the Moon, but the astronomical event happens rather rare. What ESA wanted to achieve is the capability to conduct eclipse study around the clock.

The solution its research team proposed was constructing a double-satellite system. The instruments would fly in a close, tight formation, where the one in front would cast a perennial shadow on the one in the back. This approach raises monumental engineering problems, given that both spacecraft would be flying at high speeds through space. The navigation and control systems are the most difficult aspects to set up, but the endeavor is not impossible, scientists say.

“ESA’s StarTiger is a new R&D approach, one that has paid off handsomely here. This integrated ‘breadboard’ demonstrator has been completed in just six months, including all necessary subsystems, mathematical models and software, to not only validate the external coronagraph concept but assess its performance in practical terms,” explained at yesterday's ceremony the supervisor of the initiative, expert Peter de Maagt.

“The main objective was achieved together with several secondary objectives. The idea was to perform relative positioning between the two satellites and absolute positioning with respect to the Sun. Working face-to-face in the same room was our key to success, considering the schedule we faced. We combined our various competences to solve the many problems that arose along the way,” added LAM team leader Sebastien Vives. He managed the main research group of seven experts, who were supported by 20 other investigators.

Microbial Contamination Could Hinder Search for Life on Mars

2010-04-28T21:53:00.001-04:00

Microbes and other microorganisms on the outer hull of Mars-bound spacecraft could contaminate the Red Planet with Earth-based lifeforms

After recent scientific studies demonstrated that several species of bacteria can endure in the harsh conditions of outer space for prolonged periods of time, space engineers have begun wondering on how to prevent cross-contamination in space exploration. Given the large number of mission destined for Mars that will search for signs of past life there, resolving the issues related to the possibility of cross-contamination between indigenous life forms and Earth-based microorganisms becomes of the utmost importance. New sterilization mechanisms need to be devised, and fast, scientists say.

Even if a trip to the Red Planet lasts several months at least, some species of Earth bacteria may be able to endure on the outer hull of the spacecraft. Once that particular mission reaches its destination and lands, the microorganisms could easily contaminate the Martian landscape with alien lifeforms. Scenarios related to these possible events are published in the April issue of the esteemed scientific journal Applied and Environmental Microbiology, PhysOrg reports.

The new paper is very important to the Mars Exploration Program and the Astrobiology Institutes, both NASA initiatives centered on finding life, or signs of past life, on the Red Planet. At this point, machines departing for our neighboring planet are subjected to thorough and careful decontamination procedures, which are meant to ensure that the smallest amount possible of microorganisms make their way to space, and then to Mars. However, the clean-up mechanisms are not perfect, and several kinds of microbial populations endure on the outer hull of spacecrafts, experts say.

“If long-term microbial survival is possible on Mars, then past and future explorations of Mars may provide the microbial inoculum for seeding Mars with terrestrial life. Thus, a diversity of microbial species should be studied to characterize their potential for long term survival on Mars,” say investigators from the University of Central Florida. The team here emulated Martian conditions in a test laboratory, and determined that certain bacteria, such as Escherichia coli, could survive on the planet, even though it would still have some problems multiplying.

Soviet Moon 'Mirror' Finally Identified

2010-04-28T21:52:00.000-04:00

The location of the Lunokhod 2 rover on the surface of the Moon. Its twin, Lunokhod 1, was recently found as well

Using data collected by a NASA spacecraft, experts were finally able to rediscover a long-lost, Soviet-built reflecting device on the surface of the Moon. The exact location of the scientific payload has remained a mystery since September 14, 1971. At that date, the Soviet Union lost contact with its Lunokhod 1 rover, which was carrying the mirrors. Nearly 40 years later, American physicists were able to identify the instrument using lasers beamed to the Moon all the way from Earth, Space reports.

The reflecting device itself was built by France for the Soviet Union, and it landed on the natural satellite on November 17, 1970, aboard the lander segment of the Lunokhod 1 mission. The rover was then deployed, and began its trek across the lunar surface. Eventually, in September the following year, contact with the small exploration robot was lost, and its location became a mystery. “No one had seen the reflector since 1971,” explains University of California in San Diego (UCSD) associate professor of physics Tom Murphy, who led the group that identified the Russian instrument.

This particular science team has been conducting laser experiments between Earth and the Moon for several decades. NASA has its own mirrors placed on the natural satellite, and laser beams shone on them help physicists test for gaps in Einstein's Theory of General Relativity. Light emitted from special facilities here travels to the mirrors, and then gets reflected back. The experts then look at the modifications the laser beam suffered, and calculate if the time needed for it to return is in tune with theoretical predictions based on Albert Einstein's calculations.

“We routinely use the three hardy reflectors placed on the moon by the Apollo 11, 14 and 15 missions, and occasionally the Soviet-landed Lunokhod 2 reflector – though it does not work well enough to use when illuminated by sunlight. But we yearned to find Lunokhod 1,” Murphy adds. Over the past two years, the group occasionally took some time from their work to look for the rover, but the breakthrough came only last month, when new images from the NASA Lunar Reconnaissance Orbiter (LRO) were made available.

Snapped using the Lunar Reconnaissance Orbiter Camera (LROC) instrument, the photographs were sufficiently detailed to allow for the team to identify the rover as a speck of dust in the desolate lunar landscape. The machine was located miles from where initial estimates had placed it, and from where Murphy and his team had been looking for it. Using the 3.5-meter telescope at the Apache Point Observatory, in New Mexico, the researchers sent a beam of laser light in the direction of the reflecting device, and even managed to get a hit back.

“We quickly verified the signal to be real and found it to be surprisingly bright: at least five times brighter than the other Soviet reflector, on the Lunokhod 2 rover, to which we routinely send laser pulses. The best signal we've seen from Lunokhod 2 in several years of effort is 750 return photons, but we got about 2,000 photons from Lunokhod 1 on our first try. It's got a lot to say after almost 40 years of silence,” Murphy reveals.

“Not only now do we know that Lunokhod 1 is there, we also know that it is parked perfectly so that its reflector faces Earth. In fact, the signal is so surprisingly strong that the rover could not be in anything but a level parking spot with its commanded roll on the lunar surface deliberately oriented toward the Earth,” the expert concludes.

Where comets emit dust

2010-04-27T07:38:00.000-04:00

This is a look at the comet Tempel 1 through a telescope. The active regions are responsible for the bright jets (left). With the help of their computer simulation the MPS-scientists can reconstruct the image seen from Earth (right).

Studying comets can be quite dangerous - especially from close up. Because the tiny particles of dust emitted into space from the so-called active regions on a comet's surface can damage space probes. Scientists from the Max Planck Institute for Solar System Research in Germany have now developed a computer model that can locate these regions using only the information available from Earth. The new method could help calculate a safe flight route for ESA's space probe Rosetta, which is scheduled to arrive at the comet Churyumov-Gerasimenko in 2014. (Astronomy & Astrophysics, 512, A60, 2010) A comet's nucleus is much more than an unvarying chunk of ice and dust. Under the Sun's influence, volatile substances such as water, carbon dioxide, and carbon monoxide are emitted from certain regions on its surface - the so-called active regions - carrying dust particles with a diameter of up to a few centimetres into space. Seen from Earth, these fountains of dust can be discerned as jets or spiral arms that surround the comet (see figure 1). These structures are embedded in a sheath of gas and dust called the coma that is produced by the more uniform activity of the overall surface.

"Pictures taken from Earth show the comet and its jets as a two-dimensional projection", explains Hermann Böhnhardt from the Max Planck Institute for Solar System Research (MPS). Where exactly the dust particles and gases originate from can not therefore be well identified.

In order to localize the active regions despite this problem, the MPS-researchers chose an indirect approach that for the first time also accounts for the three dimensional shape of the comet. "Until now, computer programs trying to find the active regions assumed the comet as a sphere or ellipsoid", explains Jean-Baptiste Vincent from MPS. Since in reality comets often have quite bizarre shapes, for many applications this approach is not good enough. The researchers therefore decided to take a standard approach: While watching a comet for an entire rotation period, changes in its luminance allow its true form to be calculated.

In a next step, the researchers fed their program with an initial assumption where the active regions might be located. Additionally they made an "educated guess" concerning the physical properties of the dust particles like size and initial velocity upon emission from the nucleus. As a result, the computer simulation delivers an image as it would be seen through a telescope on Earth. By comparing this with the actual image through a telescope the model can be refined step by step until simulation and actual image agree.

Already, the new method has passed its first test: The scientists could successfully apply it to the comet Tempel 1 that was the destination of NASA's Deep Impact Mission in 2005. "Even though ever since this mission we know where Tempel1's active regions are, we pretended not to", explains Vincent. For their computer program the scientists only used information that was available from Earth-base observations - apart from the nucleus shape model that was adopted from the mission results.

Next, the researchers intend to calculate the active regions of the comet Churyumov-Gerasimenko, the rendezvous target for ESA's Rosetta mission on which the Rosetta lander Philae will touch down in late 2014. The mission, to which MPS contributed many scientific instruments, has been on route to its destination beyond the orbit of Mars and the asteroid belt since 2004. In the crucial phase of the mission, the new method could help to determine a safe route for Rosetta through the cometary coma and maybe even find a suitable landing site.

Source: Max-Planck-Gesellschaft

World’s Biggest Eye on the Sky to be Located on Armazones, Chile

2010-04-27T07:34:00.001-04:00

On 26 April 2010, the ESO Council selected Cerro Armazones as the baseline site for the planned 42-metre European Extremely Large Telescope (E-ELT). Cerro Armazones is a mountain at an altitude of 3060 metres in the central part of Chile’s Atacama Desert, some 130 kilometres south of the town of Antofagasta and about 20 kilometres from Cerro Paranal, home of ESO’s Very Large Telescope.

“This is an important milestone that allows us to finalise the baseline design of this very ambitious project, which will vastly advance astronomical knowledge,” says Tim de Zeeuw, ESO’s Director General. “I thank the site selection team for the tremendous work they have done over the past few years.”

ESO’s next step is to build a European extremely large optical/infrared telescope (E-ELT) with a primary mirror 42 metres in diameter. The E-ELT will be “the world’s biggest eye on the sky” — the only such telescope in the world. ESO is drawing up detailed construction plans together with the community. The E-ELT will address many of the most pressing unsolved questions in astronomy, and may, eventually, revolutionise our perception of the Universe, much as Galileo's telescope did 400 years ago. The final go-ahead for construction is expected at the end of 2010, with the start of operations planned for 2018.

The decision on the E-ELT site was taken by the ESO Council, which is the governing body of the Organisation composed of representatives of ESO’s fourteen Member States, and is based on an extensive comparative meteorological investigation, which lasted several years. The majority of the data collected during the site selection campaigns will be made public in the course of the year 2010.

Various factors needed to be considered in the site selection process. Obviously the “astronomical quality” of the atmosphere, for instance, the number of clear nights, the amount of water vapour, and the “stability” of the atmosphere (also known as seeing) played a crucial role. But other parameters had to be taken into account as well, such as the costs of construction and operations, and the operational and scientific synergy with other major facilities (VLT/VLTI, VISTA, VST, ALMA and SKA etc).

In March 2010, the ESO Council was provided with a preliminary report with the main conclusions from the E-ELT Site Selection Advisory Committee [1]. These conclusions confirmed that all the sites examined in the final shortlist (Armazones, Ventarrones, Tolonchar and Vizcachas in Chile, and La Palma in Spain) have very good conditions for astronomical observing, each one with its particular strengths. The technical report concluded that Cerro Armazones, near Paranal, stands out as the clearly preferred site, because it has the best balance of sky quality for all the factors considered and can be operated in an integrated fashion with ESO’s Paranal Observatory. Cerro Armazones and Paranal share the same ideal conditions for astronomical observations. In particular, over 320 nights are clear per year.

Taking into account the very clear recommendation of the Site Selection Advisory Committee and all other relevant aspects, especially the scientific quality of the site, Council has now endorsed the choice of Cerro Armazones as the E-ELT baseline site [2].

“Adding the transformational scientific capabilities of the E-ELT to the already tremendously powerful integrated VLT observatory guarantees the long-term future of Paranal as the most advanced optical/infrared observatory in the world and further strengthens ESO’s position as the world-leading organisation for ground-based astronomy,” says de Zeeuw.

In anticipation of the choice of Cerro Armazones as the future site of the E-ELT and to facilitate and support the project, the Chilean Government has agreed to donate to ESO a substantial tract of land contiguous to ESO’s Paranal property and containing Armazones in order to ensure the continued protection of the site against all adverse influences, in particular light pollution and mining activities.

Explanation: Supermassive Black Hole Formation

2010-04-27T07:32:00.000-04:00

Image comment: This illustration of the black hole in Andromeda shows an old lopsided stellar disk (red) orbiting a black hole (black dot)
Image credits: NASA / ESA / A. Field

One of the greatest mysteries in the fields of astronomy and astrophysics was until recently figuring out how supermassive black holes get so big. These impressively-large formations can be found at the cores of equally-massive galaxies, and they can grow continuously until their reach masses a billion times larger than that of the Sun. For many years, various explanations have been proposed and dismissed, but now a new idea appears to hold up to thorough scientific scrutiny.

It's a widely-known fact that black holes grow by accumulating mass from their surroundings. They attract various materials, such as cosmic gas and dust, in their surroundings, and then make them a part of their accretion disks. These are the circular structures that can be found around most large black holes, from which the dark behemoth continuously draws matter. But, in the case of gas being gobbled up by these structures, astrophysicists ran into a dilemma, PhysOrg reports.

The gas has a large angular momentum, which means that it basically moves too fast to allow for the black holes to trap it into their accretion disks. So experts have been pondering on the mechanisms the formations employ in slowing the gas down sufficiently. University of California in Berkeley (UCB) astrophysicists Philip Hopkins and Eliot Quataert recently published a new study, in which they propose that old lopsided stellar disks, such as the one noticed around the black hole at the core our neighboring galaxy, Andromeda, may play a pivotal part in slowing down the swirling gas.

These disks can grow to a diameter of dozens of light-years, and, due to their lopsided nature, they tend to exert an uneven gravitational attraction on the incoming gas. This in turn causes various gas filaments within the larger clouds to collide with each other, creating friction, and reducing speed sufficiently to allow for the black hole that traps the gas with its own gravitational pull. In spite of popular belief, the dark behemoths can only gobble up gas if it passes within one light-year of their event horizon. Through this mechanism, the investigators propose, a black hole such as Andromeda's could gain several solar mass-worth of matter each year, helping to account for its current mass.

Planck Casts New Light on Stellar Formation

2010-04-27T07:29:00.001-04:00

A series of recent experiments has revealed that, more often than not, the halos of dark matter surrounding massive galaxy clusters are flattened and shaped like a cigar. Until now, astrophysicists believed that the mysterious stuff, which is believed to be five times more abundant than regular matter around the Universe, would clump up in rounded spheres. However, observations appear to paint a different picture, and experts are currently working on models that would help explain that.

The discovery could finally lead to studies that would result in the direct detection of the peculiar type of matter, whose existence can only be inferred from the gravitational pull it exerts on normal matter around it. “There are clear theoretical predictions that we expect dark mater halos to be flattened like this. It's a very beautiful, very clean and direct measurement of that,” explains expert Graham P. Smith, who is based at the University of Birmingham, in the United Kingdom. He is also a coauthor of the new study, which will appear in an upcoming issue of the esteemed scientific publication Monthly Notices of the Royal Astronomical Society.

In the new studies, the investigators looked at about 20 galaxy clusters, which are massive collections of galaxies, held together by strong gravitational interactions. In order to see the effect dark matter has on the largest organized structures in the Universe, the researchers used gravitational lensing. This observations technique analyzes how much light is bent when mass wraps time-space in order to determine the mass of celestial objects beyond. The Mauna Kea, Hawaii-based Subaru Telescope was used for the study, and the team took advantage of the Prime Focus Camera above all other instruments.

“What we're probing with these gravitational lensing observations is the dark matter distribution, because the dark matter dominates the mass on these large scales,” Smith says. The research team in charge of the study was led by National Astronomical Observatory of Japan expert Masamune Oguri and University of Tokyo scientist Masahiro Takada. The cigar-like shapes of these dark matter halos have been predicted in computer models of the cold dark matter theory, but thus far they have not been evidenced in practice in such a large number of galaxy clusters, Space reports.

“Precise measurements of the Cosmic Microwave Background are crucial to cosmology, and to understanding how our Universe formed and evolved. Attaining the highest-sensitivity (a few parts per million), highest-angular resolution (5 arcminutes) maps of the CMB – the goal of the Planck mission – requires the removal of the 'foreground' emission arising from the Milky Way. The information gleaned during this process is providing, as a by-product, a unique view of the processes that led to the formation of the stars in the galaxies that populate our Universe,” ESA officials write in a press release.

Planck maps the sky in nine frequencies using two state-of-the-art instruments, designed to produce high-sensitivity, multi-frequency measurements of the diffuse sky radiation: the High Frequency Instrument (HFI) includes the frequency bands 100 – 857 GHz, and the Low Frequency Instrument (LFI) includes the frequency bands 30-70 GHz. The first Planck all-sky survey began in August 2009 and is 98% complete (as of mid-March 2010).

Galaxy Clusters Enveloped by Cigar-Shaped Dark Matter Halos

2010-04-27T07:26:00.001-04:00

Image comment: A photo of the Bullet Cluster, one of the 20 such structures that was analyzed for the new investigation
Image credits: NASA / STScI / Magellan / U.Arizona / D.Clowe et al

Cassini to Carry Out Enceladus Flyby

2010-04-27T07:25:00.001-04:00

Since July 2004, the NASA Cassini spacecraft has been conducting remarkable scientific observations around the gas giant Saturn. In addition to looking at the planet and its intricate ring system, the probe has also carried out numerous flybys of its many moons, providing astronomers with a wealth of data about many of them, and their interactions with the ring system and Saturn's magnetosphere. An additional flyby from this series will take place today/tomorrow, as Cassini will swing by the peculiar moon Enceladus. According to mission managers, based at the NASA Jet Propulsion Laboratory, in Pasadena, California, the spacecraft will fly low above the surface of the moon, in order to conduct an intricate and sensitive gravity experiment. During the mission, planetary scientists hope to be able to extract a wealth of data as to the internal composition of Enceladus, which is undoubtedly one of the most interesting bodies in our solar system. The scheduled flight path will take the space probe about 100 kilometers (60 miles) above the surface, at the point of closest approach. This will take place on April 27 Pacific time and April 28 UTC. One of the things that makes Enceladus stand out from the crowd of Saturnine moons is the fact that astronomers believe it may house a liquid ocean. Naturally, liquid water cannot endure in the frigid temperatures of its surface, but the experts say that it may be buried several kilometers, under a thick ice crust. But the real interest is the south polar region, which featured cracks known as tiger stripes. Through these landscape features, Enceladus emits plumes of water and ice vapors, which apparently play an important role in fueling one of Saturn's rings with material. The new flyby will take Cassini straight through the plume emissions. During the flight, the instruments aboard the spacecraft will remain silent. In fact, the only thing experts need in order to conduct this experiment is a steady link between the probe and the NASA Deep Space Network on Earth. “Detecting any wiggle will help scientists understand what is under the famous "tiger stripe" fractures that spew water vapor and organic particles from the south polar region. Is it an ocean, a pond or a great salt lake? The experiment will also help scientists find out if the sub-surface south polar region resembles a lava lamp. Scientists have hypothesized that a bubble of warmer ice periodically moves up to the crust and repaves it, explaining the quirky heat behavior and intriguing surface features,” the JPL team says in a statement.

Happy 20th Birthday Hubble

2010-04-25T17:52:00.003-04:00

As the Hubble Space Telescope achieves the major milestone of two decades on orbit, NASA and the Space Telescope Science Institute, or STScI, in Baltimore are celebrating Hubble's journey of exploration with a stunning new picture and several online educational activities. There are also opportunities for people to explore galaxies as armchair scientists and send personal greetings to Hubble for posterity.

NASA is releasing a new Hubble photo of a small portion of one of the largest known star-birth regions in the galaxy, the Carina Nebula. Three light-year-tall towers of cool hydrogen laced with dust rise from the wall of the nebula. The scene is reminiscent of Hubble's classic "Pillars of Creation" photo from 1995, but even more striking.

To view the photo, visit: http://www.nasa.gov/hubble

NASA's best-recognized, longest-lived and most prolific space observatory was launched April 24, 1990, aboard the space shuttle Discovery during the STS-31 mission. Hubble discoveries revolutionized nearly all areas of current astronomical research from planetary science to cosmology.

Over the years, Hubble has suffered broken equipment, a bleary-eyed primary mirror, and the cancellation of a planned shuttle servicing mission. But the ingenuity and dedication of Hubble scientists, engineers and NASA astronauts allowed the observatory to rebound and thrive. The telescope's crisp vision continues to challenge scientists and the public with new discoveries and evocative images.

"Hubble is undoubtedly one of the most recognized and successful scientific projects in history," said Ed Weiler, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. "Last year's space shuttle servicing mission left the observatory operating at peak capacity, giving it a new beginning for scientific achievements that impact our society."

Hubble fans worldwide are being invited to take an interactive journey with Hubble by visiting http://www.nasa.gov/externalflash/Hubble20/. They can also visit http://www.hubblesite.org to share the ways the telescope has affected them. Follow the "Messages to Hubble" link to send an e-mail, post a Facebook message, or send a cell phone text message. Fan messages will be stored in the Hubble data archive along with the telescope's science data. For those who use Twitter, you can follow @HubbleTelescope or post tweets using the Twitter hashtag #hst20.

The public also will have an opportunity to become at-home scientists by helping astronomers sort out the thousands of galaxies seen in a Hubble deep field observation. STScI is partnering with the Galaxy Zoo consortium of scientists to launch an Internet-based astronomy project where amateur astronomers can peruse and sort galaxies from Hubble's deepest view of the universe into their classic shapes: spiral, elliptical, and irregular. Dividing the galaxies into categories will allow astronomers to study how they relate to each other and provide clues that might help scientists understand how they formed.

To visit the Galaxy Zoo page, go to: http://hubble.galaxyzoo.org

For educators and students, STScI is creating an educational website called "Celebrating Hubble's 20th Anniversary." It offers links to facts and trivia about Hubble, a news story that chronicles the observatory's life and discoveries, and the IMAX "Hubble 3D" educator's guide. An anniversary poster containing Hubble's "hall-of-fame" images, including the Eagle Nebula and Saturn, also is being offered with downloadable classroom activity information.

Visit the website at: http://amazing-space.stsci.edu/hubble_20

To date, Hubble has observed more than 30,000 celestial targets and amassed more than a half-million pictures in its archive. The last astronaut servicing mission to Hubble in May 2009 made the telescope 100 times more powerful than when it was launched.

For Hubble 20th anniversary image files and more information, visit:

http://hubblesite.org/news/2010/13
http://heritage.stsci.edu/2010/13
http://www.spacetelescope.org/news/html/heic1007.html

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute conducts Hubble science operations. The institute is operated for NASA by the Association of Universities for Research in Astronomy, Inc. in Washington, D.C.

Venus Express Does Aerobreaking Maneuvers

2010-04-25T17:49:00.000-04:00

The European Space Agency (ESA) has been operating the Venus Express spacecraft around the second planet from the Sun since April 2006. The instruments aboard the probe managed to collect a wealth of data about the surface and atmosphere of the space rock, and contributed considerably to our understanding of its structure. In order to boost the amount of data we have on Venus, experts at ESA conducted a series of 5 aerobreaking maneuvers in its sweltering atmosphere last week, during which the solar panels on the spacecraft were used as sails to propel it through the chemical mix.

This meant that the entire probe was basically transformed into a highly-sensitive sensor, which proved to be very suitable for assessing the density of the atmosphere above Venus, just 111 miles, or 180 kilometers, over the cloud cover that conceals its surface. “The aerodrag campaign went without problem, and conclusively demonstrated that Venus Express can be securely and accurately used to sense the density of the planet's atmosphere. Venus Express has shown once again that it is a very capable satellite,” explained the Venus Express spacecraft operations manager, Octavio Camino.

Measuring atmospheric density with a probe such as this one is fairly easy. All engineers had to do is orient its solar panels in a manner that saw a small amount of torque force being generated in the body of the spacecraft. This happened because the instrument was passing through the faintest traces of the Venusian atmosphere, which created drag. The density could then be inferred from the amount of correction that reaction wheels needed to apply in order to keep the craft in its planned trajectory in space. These wheels counter-rotate within Venus Express itself, and are considered to play a fundamental role in ensuring the success of small correction maneuvers.

According to ESA mission managers, the spacecraft is expected to continue performing such aerobreaking maneuvers well into 2011 and 2012, even though the mission was originally scheduled to end back in May 2009. Due to the amazing performances of the probe, the mission was first extended for 4 months, and then, in September 2009, it was extended to 2010. However, engineers in charge of the machine are convinced that there's still life in it, and that the mission will receive additional funding, Space reports.

US military launches top-secret robotic spacecraft

2010-04-23T06:52:00.000-04:00

A US Air Force unmanned spacecraft blasted off on Thursday from Florida, amid a veil of secrecy about its military mission.

The robotic space plane, or X-37B, lifted off from Cape Canaveral atop an Atlas V rocket at 7:52 pm local time (2352 GMT), according video released by the military.

"The launch is a go," Air Force Major Angie Blair told AFP.

Resembling a miniature space shuttle, the plane is 8.9 meters (29 feet) long and has a wing-span of 4.5 meters.

The reusable space vehicle has been years in the making and the military has offered only vague explanations as to its purpose or role in the American military's arsenal.

The vehicle is designed to "provide an 'on-orbit laboratory' test environment to prove new technology and components before those technologies are committed to operational satellite programs," the Air Force said in a recent release.

Officials said the X-37B would eventually return for a landing at Vandenberg Air Force Base in California, but did not say how long the inaugural mission would last.

"In all honesty, we don't know when it's coming back," Gary Payton, deputy undersecretary for Air Force space programs, told reporters in a conference call this week.

Payton said the plane could stay in space for up to nine months.

Flight controllers plan to monitor the vehicle's guidance, navigation and control systems, but the Air Force has declined to discuss what the plane is carrying in its payload or what experiments are scheduled.

Pentagon officials have sidestepped questions about possible military missions for the spacecraft, as well as the precise budget for its development -- estimated at hundreds of millions of dollars.

The results of the test flight will inform "development programs that will provide capabilities for our warfighters in the future," Payton said.

The space plane -- manufactured by Boeing -- began as a project of NASA in 1999, and was eventually handed over to the US Air Force Rapid Capabilities Office.

The Air Force has plans for a second X-37B, scheduled to launch in 2011.

LUCIFER Allows Astronomers to Watch Stars Being Born

2010-04-23T06:47:00.000-04:00

A new instrument for the world's largest optical telescope, the Large Binocular Telescope on Mount Graham, allows astronomers to observe the faintest and most distant objects in the universe.

Large Binocular Telescope (LBT) partners in the U.S, Germany and Italy announced April 21 that the first of two new innovative near-infrared cameras/spectrographs for the LBT is now available to astronomers for scientific observations at the telescope on Mount Graham in southeastern Arizona.

After more than a decade of design, manufacturing and testing, the new instrument - dubbed LUCIFER 1 - provides a powerful tool to gain spectacular insights into the universe - from the Milky Way to extremely distant galaxies. LUCIFER, built by a consortium of German institutes, will be followed by an identical twin instrument that will be delivered to the telescope in early 2011.

"With the large light-gathering power of the LBT, astronomers are now able to collect the spectral fingerprints of the faintest and most distant objects in the universe," said LBT director Richard Green, a professor of astronomy at the University of Arizona's Steward Observatory.

LUCIFER 1 and its twin are mounted at the focus points of the LBT's two giant 8.4-meter (27.6 foot) diameter telescope mirrors. Each instrument is cooled to -213 degrees Celsius in order to observe in the near-infrared wavelength range.

Near-infrared observations are essential for understanding the formation of stars and planets in our galaxy as well as revealing the secrets of the most distant and very young galaxies.

LUCIFER's innovative design allows astronomers to observe in unprecedented detail, for example star forming regions, which are commonly hidden by dust clouds.

The instrument is remarkably flexible, combining a large field of view with a high resolution. It provides three exchangeable cameras for imaging and spectroscopy in different resolutions according to observational requirements.

Astronomers use spectroscopy to analyze incoming light and answer questions such as how stars and galaxies formed and what they are made of.

Pulsars in many octaves

2010-04-22T19:47:00.000-04:00

Simultaneous detection of pulses from pulsar PSR B1133+16 in four widely spaced bands, using the Effelsberg telescope at 3.5 cm wavelength, the Lovell telescope at 21 cm wavelength, and LOFAR high-band (HBAs) and low-band antennas (LBAs) at 170 cm and 430 cm wavelength, respectively. The shape of the pulsar's pulsed emission maps the spreading of magnetic field lines above the pulsar's magnetic poles.

A unique combination of telescopes allowed astronomers to simultaneously observe the radio wavelength light from six different pulsars across wavelengths from only 3.5 centimetres up to 7 metres - a difference-factor of 200, providing an unprecedented view of how radio pulsars shine. For this world record in wavelength coverage, the international team, including scientists from the Max Planck Institute for Radio Astronomy, used the new European LOFAR telescope, in combination with two of the world's largest radio telescopes, the 100 metre Effelsberg telescope in Germany and the 76 metre Lovell telescope in the United Kingdom. Pulsars are rapidly rotating neutron stars, which measure only about 20 kilometres across and yet are more massive than the Sun. They produce beams of radio light from their magnetic poles, which are observable over a wide range of wavelengths. For the last 40 years astronomers have been studying pulsars and have been getting closer to understanding the mechanism that generates these intense beams. They hypothesize that the emission seen at the different wavelengths emerges from different heights above the highly magnetized pulsar surface. Emission seen at a particular radio wavelength therefore provides a slice through the pulsar's surrounding "magnetosphere" (magnetized atmosphere).

Astronomers believe that pulsar emission at different radio wavelengths may be created at different heights above the star's magnetic poles. The magnetic field lines that accelerate particles spread apart as one moves further and further away from the pulsar's surface. Experimental support for this hypothesis is the observation that the pulses of some pulsars become stretched out at long wavelengths (Fig. 1). The shape of the pulsar's pulsed emission is seen to evolve quite drastically as a function of wavelength and maps the spreading of magnetic field lines above the pulsar's magnetic poles.

With any single telescope, a pulsar can only be observed in a relatively narrow range of wavelengths at any given time. By combining the traditional large Effelsberg and Lovell telescopes, observing at wavelengths of centimetres, with the next generation telescope LOFAR, observing at wavelengths of meters, the astronomers were able to observe a set of six pulsars, each simultaneously across a range of nearly 8 octaves. "For comparison, consider that we have simultaneously observed these pulsars over a range equivalent to all the tones spanned by a piano," says Jason Hessels of ASTRON Netherlands Institute for Radio Astronomy. "By simultaneously observing these pulsars at such a wide range of wavelengths, we can make many snapshots of what the pulsar's emission looks like at a range of heights above the star's magnetic poles," he adds.

Key to these observations was the use of the new LOFAR telescope, which has a collection of thousands of radio antennas in stations that are centred near Exloo, in the Netherlands, and that spread from there over distances of hundreds of kilometres into neighbouring countries, such as France, Germany, Sweden, and the United Kingdom. The data taken on all stations are brought together for data analysis via high-speed networks to a BlueGene/P supercomputer and powerful cluster computers at the University of Groningen Centre for Information Technology. LOFAR is operated as an integrated facility from the ASTRON headquarters in Dwingeloo, the Netherlands. The LOFAR telescope is currently being prepared for full-scale scientific observations, and the astronomers were excited to make such high-quality, pulsar measurements even in the testing phase.

Michael Kramer, director at the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn, is excited about the enormous extension in wavelength coverage provided by LOFAR, of which the first international antenna station was built next to the Effelsberg telescope in Germany. "These observations show how LOFAR complements the existing radio telescopes in Europe, like the 100-m Effelsberg telescope, in an almost perfect way."

These observations have the primary goal of better understanding how pulsars pulse. However, there is also much to be learned beyond studying just the pulsar itself. "Not only do such observations give us a fantastic handle on understanding the emission of pulsars, they are also a powerful probe of the interstellar gas that is between us and the pulsar," says Ben Stappers of the University of Manchester.

"We are really excited to have the first international LOFAR station operating here in direct vicinity to the giant 100m Effelsberg radio telescope", says Kosmas Lazaridis from MPIfR. "The combination of both, large parabolic dishes for the centimetre regime, and new digital technology for the longer wavelengths provides a wealth of new data for our pulsar research programs."

The LOFAR telescope, spanning more than 1000 kilometres in Europe, will be completed in the next year and will be the most powerful telescope on Earth for observing the Universe at the longest possible radio wavelengths visible from the Earth's surface: 1-30 metres. It is expected that this will produce a flood of exciting new scientific results.

Source: Max-Planck-Gesellschaft

Surfing an alien atmosphere

2010-04-21T22:46:00.000-04:00

Venus Express has completed an 'aerodrag' campaign that used its solar wings as sails to catch faint wisps of the planet’s atmosphere. The test used the orbiter as an exquisitely accurate sensor to measure atmospheric density barely 180 km above the hot planet.

During five aerodrag measurements last week, Venus Express' solar arrays and control systems were operated as one big flying sensor, with the solar arrays rotated at various angles to the direction of flight.

The special configuration exposed the wings to the vanishingly faint wisps of atmosphere that reach to the boundary of space around Venus, generating a tiny but measurable aerodynamic torque, or rotation, on the satellite.

This torque can be measured very accurately based on the amount of correction that must be applied by reaction wheels, which counter-rotate inside the spacecraft to maintain its orientation in space.

Mimicking the vanes of a windmill

Starting on Monday, the solar panels rotated through five daily-changing sets of orientations. While one panel remained perpendicular to the direction of flight, the other rotated in steps, gradually increasing the torque to be counter-balanced by the reaction wheels.

On the last day, 16 April, the solar arrays were rotated at plus and minus 45° to the atmospheric flow, mimicking the vanes of a windmill, in order to gather additional information on the behaviour of the molecules of the atmosphere bouncing off the solar wings.

A very capable satellite

"The aerodrag campaign went without problem, and conclusively demonstrated that Venus Express can be securely and accurately used to sense the density of the planet's atmosphere. Venus Express has shown once again that it is a very capable satellite," said Spacecraft Operations Manager Octavio Camino.

Camino explained that the mission operations team will study last week’s results to develop an optimised configuration for aerodrag campaigns in October and in 2011. Aerodrag testing was also conducted in 2008, 2009 and February 2010.

Continued positive results may enable Venus Express to conduct more sophisticated investigations deeper in the atmosphere, which would be of immense interest to planetary scientists.

The solar array on Venus Express comprise two symmetrical wings supporting gallium-arsenide solar cells. Their combined 5.7 sq m can generate up to 1400 W of power in Venus orbit.

Source:- ESA

VISTA Captures Celestial Cat’s Hidden Secrets

2010-04-21T22:39:00.000-04:00

The Cat’s Paw Nebula, NGC 6334, is a huge stellar nursery, the birthplace of hundreds of massive stars. In a magnificent new ESO image taken with the Visible and Infrared Survey Telescope for Astronomy (VISTA) at the Paranal Observatory in Chile, the glowing gas and dust clouds obscuring the view are penetrated by infrared light and some of the Cat’s hidden young stars are revealed.

Towards the heart of the Milky Way, 5500 light-years from Earth in the constellation of Scorpius (the Scorpion), the Cat’s Paw Nebula stretches across 50 light-years. In visible light, gas and dust are illuminated by hot young stars, creating strange reddish shapes that give the object its nickname. A recent image by ESO’s Wide Field Imager (WFI) at the La Silla Observatory (eso1003) captured this visible light view in great detail. NGC 6334 is one of the most active nurseries of massive stars in our galaxy.

VISTA, the latest addition to ESO’s Paranal Observatory in the Chilean Atacama Desert, is the world’s largest survey telescope (eso0949). It works at infrared wavelengths, seeing right through much of the dust that is such a beautiful but distracting aspect of the nebula, and revealing objects hidden from the sight of visible light telescopes. Visible light tends to be scattered and absorbed by interstellar dust, but the dust is nearly transparent to infrared light.

VISTA has a main mirror that is 4.1 metres across and it is equipped with the largest infrared camera on any telescope. It shares the spectacular viewing conditions with ESO’s Very Large Telescope (VLT), which is located on the nearby summit. With this powerful instrument at their command, astronomers were keen to see the birth pains of the big young stars in the Cat’s Paw Nebula, some nearly ten times the mass of the Sun. The view in the infrared is strikingly different from that in visible light. With the dust obscuring the view far less, they can learn much more about how these stars form and develop in their first few million years of life. VISTA’s very wide field of view allows the whole star-forming region to be imaged in one shot with much greater clarity than ever before.

The VISTA image is filled with countless stars of our Milky Way galaxy overlaid with spectacular tendrils of dark dust that are seen here fully for the first time. The dust is sufficiently thick in places to block even the near-infrared radiation to which VISTA’s camera is sensitive. In many of the dusty areas, such as those close to the centre of the picture, features that appear orange are apparent — evidence of otherwise hidden active young stars and their accompanying jets. Further out though, slightly older stars are laid bare to VISTA’s vision, revealing the processes taking them from their first nuclear fusion along the unsteady path of the first few million years of their lives.

The VISTA telescope is now embarking on several big surveys of the southern sky that will take years to complete. The telescope’s large mirror, high quality images, sensitive camera and huge field of view make it by far the most powerful infrared survey telescope on Earth. As this striking image shows, VISTA will keep astronomers busy analysing data they could not have otherwise acquired. This cat is out of the bag.

Source:- ESO

Making the invisible visible: New workhorse for the world’s largest optical telescope

2010-04-21T22:35:00.003-04:00

A snapshot of a stellar nursery in our home galaxy, the Milky Way: a high-mass star forming region inside the giant molecular cloud S255, about 8,000 light-years away from Earth (1 light-year is roughly 10 trillion kilometers). Such clouds are typically opaque to visible light. However, infrared light can penetrate the dust, so that the LUCIFER image reveals the cluster of newly born stars and its complex environment in all their splendour. Image: Arjan Bik

The Large Binocular Telescope (LBT) partners in Germany, the U.S.A. and Italy are pleased to announce that the first of two new innovative near-infrared cameras/spectrographs for the LBT is now available to astronomers for scientific observations at the telescope on Mt. Graham in south-eastern Arizona. After more than a decade of design, manufacturing and testing, the new instrument, dubbed LUCIFER 1, provides a powerful tool to gain spectacular insights into the universe, from the Milky Way up to extremely distant galaxies. LUCIFER 1 has been built by a consortium of German institutes and will be followed by an identical twin instrument that will be delivered to the telescope in early 2011.

LUCIFER’s innovative design allows astronomers to observe in unprecedented detail, for example, star forming regions which are commonly hidden by dust clouds. The instrument provides unrivaled flexibility, with features such as a unique robotic arm that can replace spectroscopic masks within the instrument’s extreme sub-zero environment.

LUCIFER and its twin are mounted at the focus points of the LBT’s two giant 8.4-metre (27.6 foot) diameter telescope mirrors. Each instrument is cooled to a chilly -213 degrees Celsius in order to observe in the near-infrared (NIR) wavelength range. Near-infrared observations are essential for understanding the formation of stars and planets in our galaxy as well as revealing the secrets of the most distant and very young galaxies.

LUCIFER is a remarkable new multi-purpose instrument with great flexibility combining a large field of view with a high resolution. It provides three exchangeable cameras for imaging and spectroscopy in different resolutions according to observational requirements. Besides its outstanding imaging capability which presently makes use of 18 high-quality filters, LUCIFER allows the simultaneous spectroscopy of about two dozen objects in the infrared through laser-cut slit-masks. For highest flexibility the masks can be changed even at the cryogenic temperatures, through the innovative development of a unique robotic mask grabber which places the individual masks with absolute precision into the focal plane.

"Together with the large light gathering power of the LBT, astronomers are now able to collect the spectral fingerprints of the faintest and most distant objects in the universe." says Richard Green, the Director of the LBT. "After completion of the LBT adaptive secondary mirror system to correct for atmospheric perturbation, LUCIFER will show its full capability by delivering images with a quality that are otherwise only obtained from space-based observatories."

"Already the very first LUCIFER observations of star forming regions are giving us an indication of the enormous potential of the new instrument," said Thomas Henning, the chair of the German LBT-Partners.

The instruments have been built by a consortium of five German institutes led by the Center for Astronomy of Heidelberg University (Landessternwarte Heidelberg, LSW) together with the Max Planck Institute for Astronomy in Heidelberg (MPIA), the Max Planck Institute for Extraterrestrial Physics in Garching (MPE), the Astronomical Institute of the Ruhr-University in Bochum (AIRUB) as well as the University of Applied Sciences in Mannheim (Hochschule Mannheim).

Walter Seifert (LSW), Nancy Ageorges (MPE) and Marcus Jütte (AIRUB), responsible for the successful commissioning, spent more than half a year in several runs at the LBT site to make the telescope/instrument combination work efficiently. Holger Mandel, the Principal Investigator of LUCIFER said: "From the very beginning, there was uniform excitement about the promise of this instrument for cutting-edge science. Now, the amazing results speak for themselves."

Source:- Max Planck Society

NASA's Spitzer Space Telescope Discovers Extrasolar Planet Lacking Methane

2010-04-21T22:31:00.001-04:00

PASADENA, Calif. - NASA's Spitzer Space Telescope has discovered something odd about a distant planet -- it lacks methane, an ingredient common to many of the planets in our solar system.

"It's a big puzzle," said Kevin Stevenson, a planetary sciences graduate student at the University of Central Florida in Orlando, lead author of a study appearing tomorrow, April 22 in the journal Nature. "Models tell us that the carbon in this planet should be in the form of methane. Theorists are going to be quite busy trying to figure this one out."

The discovery brings astronomers one step closer to probing the atmospheres of distant planets the size of Earth. The methane-free planet, called GJ 436b, is about the size of Neptune, making it the smallest distant planet that any telescope has successfully "tasted," or analyzed. Eventually, a larger space telescope could use the same kind of technique to search smaller, Earth-like worlds for methane and other chemical signs of life, such as water, oxygen and carbon dioxide.

"Ultimately, we want to find biosignatures on a small, rocky world. Oxygen, especially with even a little methane, would tell us that we humans might not be alone," said Stevenson.

"In this case, we expected to find methane not because of the presence of life, but because of the planet's chemistry. This type of planet should have cooked up methane. It's like dipping bread into beaten eggs, frying it, and getting oatmeal in the end," said Joseph Harrington of the University of Central Florida, the principal investigator of the research.

Methane is present on our life-bearing planet, manufactured primarily by microbes living in cows and soaking in waterlogged rice fields. All of the giant planets in our solar system have methane too, despite their lack of cows. Neptune is blue because of this chemical, which absorbs red light. Methane is a common ingredient of relatively cool bodies, including "failed" stars, which are called brown dwarfs.

In fact, any world with the common atmospheric mix of hydrogen, carbon and oxygen, and a temperature up to 1,000 Kelvin (1,340 degrees Fahrenheit) is expected to have a large amount of methane and a small amount of carbon monoxide. The carbon should "prefer" to be in the form of methane at these temperatures.

At 800 Kelvin (or 980 degrees Fahrenheit), GJ 436b is supposed to have abundant methane and little carbon monoxide. Spitzer observations have shown the opposite. The space telescope has captured the planet's light in six infrared wavelengths, showing evidence for carbon monoxide but not methane.

"We're scratching our heads," said Harrington. "But what this does tell us is that there is room for improvement in our models. Now we have actual data on faraway planets that will teach us what's really going on in their atmospheres."

GJ 436b is located 33 light-years away in the constellation Leo, the Lion. It rides in a tight, 2.64-day orbit around its small star, an "M-dwarf" much cooler than our sun. The planet transits, or crosses in front of, its star as viewed from Earth.

Spitzer was able to detect the faint glow of GJ 436b by watching it slip behind its star, an event called a secondary eclipse. As the planet disappears, the total light observed from the star system drops -- this drop is then measured to find the brightness of the planet at various wavelengths. The technique, first pioneered by Spitzer in 2005, has since been used to measure atmospheric components of several Jupiter-sized exoplanets, the so-called "hot Jupiters," and now the Neptune-sized GJ 436b.

"The Spitzer technique is being pushed to smaller, cooler planets more like our Earth than the previously studied hot Jupiters," said Charles Beichman, director of NASA's Exoplanet Science Institute at NASA's Jet Propulsion Laboratory and the California Institute of Technology, both in Pasadena, Calif. "In coming years, we can expect that a space telescope could characterize the atmosphere of a rocky planet a few times the size of the Earth. Such a planet might show signposts of life."

This research was performed before Spitzer ran out of its liquid coolant in May 2009, officially beginning its "warm" mission.

Other authors include: Sarah Nymeyer, William C. Bowman, Ryan A. Hardy and Nate B. Lust from the University of Central Florida; Nikku Madhusudhan and Sara Seager of the Massachusetts Institute of Technology, Cambridge; Drake Deming of NASA's Goddard Space Flight Center, Greenbelt, Md.; and Emily Rauscher of Columbia University, New York.

JPL manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at Caltech. Caltech manages JPL for NASA. For more information about Spitzer, visit http://www.spitzer.caltech.edu/spitzer and http://www.nasa.gov/spitzer.

Nasa's Solar Dynamics Observatory returns first images

2010-04-21T22:26:00.002-04:00

The first public release of images from the satellite record huge explosions and great looping prominences of gas.

The observatory's super-fine resolution is expected to help scientists get a better understanding of what drives solar activity.

Launched in February on an Atlas rocket from Cape Canaveral, SDO is expected to operate for at least five years.

Researchers hope in this time to go a long way towards their eventual goal of being able to forecast the effects of the Sun's behaviour on Earth.

Solar activity has a profound influence on our planet. Huge eruptions of charged particles and the emission of intense radiation can disrupt satellite, communication and power systems, and pose a serious health risk to astronauts.

Scientists working on SDO say they are thrilled with the quality of the data received so far.

"When we see these fantastic images, even hard-core solar physicists like myself are struck with awe, literally," said Lika Guhathakurta, the SDO programme scientist at Nasa Headquarters.

SDO is equipped with three instruments to investigate the physics at work inside, on the surface and in the atmosphere of the Sun.

The probe views the entire solar disc with a resolution 10 times better than the average high-definition television camera. This allows it to pick out features on the surface and in the atmosphere that are as small as 350km across.

The pictures are also acquired at a rapid rate, every few seconds.

In addition, the different wavelengths in which the instruments operate mean scientists can study the Sun's atmosphere layer by layer.

A key quest will be to probe the inner workings of the solar dynamo, the deep network of plasma currents that generates the Sun's tangled and sometimes explosive magnetic field.

It is the dynamo that ultimately lies behind all forms of solar activity, from the solar flares that explode in the Sun's atmosphere to the relatively cool patches, or sunspots, that pock the solar disc and wander across its surface for days or even weeks.

"The SDO images are stunning and the level of detail they reveal will undoubtedly lead to a new branch of research into how the fine-scale solar magnetic fields form and evolve, leading to a much, much better understanding of how solar activity develops," said co-investigator Richard Harrison from the UK's Rutherford Appleton Laboratory (RAL).

"It's like looking at the details of our star through a microscope," he told BBC News.

And Dr Guhathakurta added: "It's thought that [SDO] is going to revolutionise heliophysics much as the Hubble Space Telescope has revolutionised astrophysics and cosmology, which is true. There is however a very key difference. While Hubble is designed to observe almost everything in the cosmos, SDO is designed to study only one thing and that is our very own star. It is tailor-made for the study of Sun star."

SDO's three remote-sensing instruments are:

Helioseismic and Magnetic Imager (HMI) : will study the motions and magnetic fields at the Sun's surface, or photosphere, to determine what is happening inside the star. It will try to decipher the physics of the solar dynamo - the very source of the Sun's activity. The dynamo regulates all forms of solar activity from the lightning-fast eruptions of solar flares to the slow decadal undulations of the sunspot cycle.

Atmospheric Imaging Assembly (AIA) : is a suite of four telescopes that will image the corona, the outer layer of the Sun's atmosphere. The AIA filters cover 10 different wavelength bands, or colours, from the extreme ultraviolet to the visible. It will see details as small as 725km across. These images will be acquired every 10 seconds. Previous observatories have taken pictures at best every few minutes.

Extreme Ultraviolet Variability Experiment (EVE) : will measure the Sun's energy output in extreme-ultraviolet (E-UV) wavelengths (this is called irradiance) with unprecedented precision. The Sun is at its most variable in the E-UV. E-UV rays can break apart atoms and molecules in the Earth's upper-atmosphere, creating a layer of ions that can severely disturb radio signals.

The UK has a prominent role in the mission through the Rutherford Appleton Laboratory in Didcot; the e2v company in Chelmsford which supplied CCD camera detectors; the Mullard Space Science Laboratory in London; the University of Warwick; the University of Sheffield; and the University of Central Lancashire (UCLan) in Preston.

UCLan handles the SDO data coming into the UK. With the mission producing some 1.5 tera-bytes per day, it requires a dedicated gateway for scientists to exploit.

Source:- SDO

Dark matter may give neutron stars black hearts

2010-04-20T22:22:00.000-04:00

DARK matter may be prompting black holes to appear spontaneously in the hearts of distant exotic stars. If so, this could hint at the nature of dark matter.

Arnaud de Lavallaz and Malcolm Fairbairn of King's College London wondered what would happen when dark matter - which makes up most of the mass of galaxies - is sucked into the heart of neutron stars. These stars, the remnants of supernova explosions, are the densest known stars in the universe. It turns out that the outcome depends on the nature of dark matter.

Most of the favoured theories of dark matter suggest each particle of the stuff is also an antiparticle, meaning that they should annihilate each other when they meet. But Fairbairn and de Lavallaz considered a dark matter particle of a different type, which is not also its antiparticle.

The pair calculated what would happen if dark matter particles like these were attracted by the intense gravity of neutron stars. Because they would not annihilate each other, the dark matter particles would end up forming a smaller, dense star at the heart of the neutron star. If the neutron star were near the centre of the galaxy, for example, and surrounded by an abundance of dark matter, then it would continue to accrete dark matter.

Eventually, the mass of the dark matter star would exceed its "Chandrashekar limit" - beyond which a star cannot withstand gravitational pressure. The dark matter star would collapse into a black hole. "Then the neutron star won't be able to survive anymore, and it'll collapse too," says Fairbairn. "It would be pretty catastrophic."

Their calculations show that if a neutron star collapsed in this way the result would be a burst of gamma rays, which could be spotted from Earth (arxiv.org/abs/1004.0629).

Various underground experiments back on Earth have been trying to detect dark matter, using different techniques. While none of the major experiments have seen anything yet, physicists running the Dark Matter (DAMA) experiment inside the Gran Sasso mountain in Italy have been saying for some time that dark matter particles are hitting their detector. Most physicists are sceptical of the DAMA results because it doesn't sit well with favoured theories on the nature of dark matter.

Fairbairn says that the DAMA experiment could be sensitive to dark matter particles that do not self-annihilate, which might explain why it is seeing something and others are not.

Source: NewScientist.com

X-37B robotic space plane aims for Thursday launch

2010-04-20T22:06:00.001-04:00

LOS ANGELES – The military is poised to launch an unmanned winged spacecraft resembling a miniature space shuttle Thursday and it probably won't be a one-time shot.

Gary Payton, Air Force deputy under secretary for space programs, said Tuesday the Air Force has contracted for a second space plane depending on the success of the prototype's maiden flight.

"Currently, we're looking at a 2011 launch for that second tail number. That assumes everything goes properly as predicted on this first flight," Payton told reporters.

After a decade of development, the X-37B Orbital Test Vehicle is slated to launch from Florida and spend up to nine months in orbit. It will re-enter Earth on autopilot and land like an airplane at the Vandenberg Air Force Base, Calif.

The spacecraft will conduct classified experiments while in orbit. Payton said the Air Force's main interest is to test the craft's automated flight control system and learn about the cost of turning it around for launch again.

Built by Boeing's Phantom Works division, the X-37 program was originally headed by NASA. It was later turned over to the Pentagon's research and development arm and then to a secretive Air Force unit.

Hundreds of millions of dollars have been spent on the project, but the current total has not been released.

"After a tumultuous history of sponsorship, it's great to see the X37 finally get to the launch pad and get into space," Payton said.

Mars Odyssey THEMIS images - April 12-16, 2010

2010-04-20T22:05:00.001-04:00

The following new images taken by the Thermal Emission Imaging System (THEMIS) on the Mars Odyssey spacecraft are now available:

Candor Chasma (Released 12 April 2010)
This VIS image of Candor Chasma contains eroded deposits of material and a large landslide deposit.
Hecates Tholus (Released 13 April 2010)
This VIS image shows the southeastern flank of Hecates Tholus, the northernmost volcano of the Elysium Volcanic complex.
Terra Sabaea (Released 14 April 2010)
The northern part of Terra Sabaea is heavily fractured and channeled, breaking up into a chaotic terrain as the elevation drops down to the northern plains.
Arabia Terra (Released 15 April 2010)
Dark slope streaks mark this crater rim.
Coprates Chasma (Released 16 April 2010)
This VIS image shows a portion of the floor of Coprates Chasma.

Cassini ISS images - April 12-16, 2010

2010-04-20T22:04:00.002-04:00

The following new images taken by the Imaging Science Subsystem (ISS) on the Cassini spacecraft are now available:

Before Hazy Titan (Released 12 April 2010)
Saturn's moon Dione passes in front of the larger moon Titan, as seen from the Cassini spacecraft.
Lost Among Stars (Released 13 April 2010)
Saturn's tiny moon Atlas appears almost indistinguishable from the background stars seen in this Cassini spacecraft image.
Up and Down Tethys (Released 14 April 2010)
The Cassini spacecraft profiles several features oriented north-south on Saturn's moon Tethys.
In the Arc (Released 15 April 2010)
This Cassini spacecraft image holds an unseen treasure orbiting within the bright arc of Saturn's G ring: the tiny moonlet Aegaeon.
Map of Dione - February 2010 (Released 15 April 2010)
This global map of Saturn's moon Dione was created using images taken during flybys by NASA's Cassini spacecraft.
Dione Polar Maps - February 2010 (Released 15 April 2010)
The northern hemisphere of Saturn's moon Dione is seen in this polar stereographic maps, mosaicked from the best-available clear-filter images from NASA's Cassini and Voyager missions.
Dione Polar Maps - February 2010 (Released 15 April 2010)
The southern hemisphere of Saturn's moon Dione is seen in this polar stereographic maps, mosaicked from the best-available clear-filter images from NASA's Cassini and Voyager missions.
Brilliant Blip Beyond Saturn (Released 16 April 2010)
The highly reflective moon Enceladus appears as a bright dot beyond a crescent Saturn in this Cassini image.

Lunar Reconnaissance Orbiter LROC images - April 13-16, 2010

2010-04-20T22:04:00.001-04:00

The following featured images taken by the Lunar Reconnaissance Orbiter Camera (LROC) are now available:

The Apollo 15 Lunar Laser Ranging Retroreflector - A Fundamental Point on the Moon! (Released 13 April 2010)
The Apollo 15 Lunar Laser Ranging RetroReflector (LRRR) array is one of four such working arrays on the surface of the Moon.
Exposed Fractured Bedrock in the Central Peak of the Anaxagoras Crater (Released 14 April 2010)
NAC image of the Anaxagoras crater floor, including a portion of the crater's anorthositic central uplift.
Rimae Prinz Region - Constellation Region of Interest (Released 15 April 2010)
A sinuous rille created by a lava flow snakes around the base of a massif in the Prinz-Harbinger region on the Moon.
Retracing the Steps of Apollo 15: Constellation Region of Interest (Released 16 April 2010)
The third and final EVA of Apollo 15 brought the astronauts to the edge of Hadley Rille (lower left).

Discovery returns to Earth

2010-04-20T22:01:00.000-04:00

HOUSTON, Texas (AFP) – Discovery made a safe return to Earth Tuesday after a two-week resupply mission to the International Space Station that broke new ground by putting four women in orbit for the first time.

The shuttle and its seven-member crew finally touched down at NASA's Kennedy Space Center in Florida at 9:08 am (1308 GMT) after a series of earlier delays due to rain and fog.

"Welcome home. Congratulations on an outstanding mission," Mission Control said after the Discovery put more women in orbit than ever before, with three female crew joining one woman already on the space station.

"What a great mission," replied Discovery commander Alan Poindexter. "We enjoyed it."

The mission also marked the first time that two Japanese astronauts were in space at the same time, with Discovery mission specialist Naoko Yamazaki joining Soichi Noguchi of the Japan Aerospace Exploration Agency.

And it signaled a growing awareness among NASA's ground team and astronauts that the vaunted shuttle program is winding down, marking the end of an era in human spaceflight.

"It's a little bit bittersweet, but we do have to recognize that like anything else, there does have to be an end to any major program," said Pete Nickolenko, NASA's launch director, during a post-landing news briefing.

"We recognize that we are facing that, that we are coming up to it," he said.

Meanwhile, Bryan Lunney, the NASA flight director who supervised Discovery's descent and will also oversee the final shuttle flight, said it is a bit too early to get misty-eyed.

"For me, we are heads down focused on the mission, trying to make sure it's safe and successful," he said.

"I haven't gotten too philosophical or concerned about the future. I'm just taking care of business," Lunney said.

Discovery dropped from orbit Tuesday over the Pacific Ocean and followed a rare course that took it over much of the US upper Midwest and Southeast, leaving a glowing contrail for ground observers.

The shuttle's crew delivered nearly eight tonnes of scientific equipment and other supplies intended to fortify the orbiting science laboratory for operations well beyond the final shuttle flight.

The new research gear includes an Earth observation rack to hold cameras and spectral scanners for studies of the atmosphere, geological formations, and weather-induced crop damage.

Another new experiment monitors changes in the muscle and joint health of the astronauts in the absence of gravity. A new freezer will store specimens for medical and biological experiments.

During three spacewalks, two of the astronauts wrestled with bulky bolts to replace a boxy coolant tank that is essential to the long-term function of the station's life support systems.

Discovery has only one more flight before it is mothballed, while NASA counts just three more missions until it retires its entire shuttle fleet and embarks on a new phase in human spaceflight.

The US space agency will have to turn to Russia to transport Americans to the orbiting science laboratory while it tries to foster a commercial space taxi industry.

President Barack Obama has drawn fire for shelving plans outlined by his predecessor George W. Bush -- which he argues are too costly -- for NASA to develop a new generation of spacecraft for missions to the moon and Mars.

Shuttle Atlantis will fly next, with a lift off tentatively scheduled for May 14.

During its 12-day mission, six astronauts will deliver a Russian mini-research module and external spare parts, including power storage batteries, a communications antenna and a radiator as well as Canadian and European robot arm components.

Endeavour is to follow, with a launch scheduled for July 29. Its cargo includes the Alpha Magnetic Spectrometer, an internationally-sponsored physics investigation for the study of cosmic radiation and anti-matter.

If the scheduling holds, Discovery will lift off for the station on September 16 for the final shuttle flight carrying yet more cargo and a pressurized storage module.

NRL Researchers Study Galaxy Mergers

2010-04-20T21:49:00.001-04:00

The University of Hawaii 2.2-meter telescope.

Scientists at the Naval Research Laboratory have solved a long-standing dilemma about the mass of infrared bright merging galaxies. Because galaxies are the largest directly observable objects in the universe, learning more about their formation is key to understanding how the universe works.

Dr. Barry Rothberg and Dr. Jacqueline Fischer, both of the Infrared-Submillimeter Astrophysics & Techniques Section in the Remote Sensing Division, used new data from the 8-meter Gemini-South telescope in Chile along with earlier results from the W. M. Keck-2 10-meter and University of Hawaii 2.2-meter telescopes in Hawaii and archival data from the Hubble Space Telescope, to solve the problem. They have published a paper on their research findings on galaxy evolution in the Astrophysical Journal (March 20, 2010 Volume 712).

Galaxies in the Universe generally come in two shapes, spiral, like our own Milky Way, and elliptical, in which the stars move in random orbits, Rothberg explains. The largest galaxies in the Universe are elliptical in shape and how they formed is central to our understanding how the Universe has evolved over the last 15 billion years. The long-standing theory has been that spiral galaxies merge with each other forming most of the elliptical galaxies in the Universe. Spiral galaxies contain significant amounts of cold hydrogen gas. When they merge, the beautiful spiral patterns are destroyed and the gas is converted into new stars. The more gas present in the spiral galaxies, the more stars are formed and with it, large amounts of dust. The dust is heated by the young stars and radiates energy at infrared wavelengths.

Until recently scientists thought that these infrared bright merging galaxies were not massive enough to be the precursors of most elliptical galaxies in the Universe. The problem lay in the method of measuring their mass. The conventional method of measuring mass in dusty IR-bright galaxies uses near-infrared light to measure the random motions of old-stars. The larger the random motions, the more mass is present. Using near-infrared light makes it possible to penetrate the dust and see as many of the old stars as possible. However, a complication occurs when spiral galaxies merge, because most of their gas is funneled to the gravitational center of the system and forms a rotating disk. This rotating disk of gas is transformed into a rotating disk of young stars that is also very bright at near-infrared wavelengths. The rotating disk of young stars both outshines the old stars and makes it appear as if the old stars have significantly less random motion. In contrast to this conventional method, Rothberg and Fischer instead observed the random motions of old stars at shorter wavelengths effectively using the dust to their advantage to block the light from the young stars. Their new results showed that the old stars in merging galaxies have large random motions, which means they will eventually become very massive elliptical galaxies.

The next step for NRL researches is to directly observe the stellar disks in IR luminous mergers using three-dimensional spectroscopy. Each pixel is a spectrum, and from this the researchers can make two-dimensional maps of stellar motion and stellar age. This will allow them to measure the size, rotation, luminosity, mass and age of the central disk.

Source:- NRL

Remarks of President Barack Obama Space Exploration in the 21st Century

2010-04-19T20:21:00.002-04:00

The President's speech opened a conference on the new course for NASA and the future of the U.S. in human spaceflight. › Feature Story | › Photos, Videos, and Other Resources | › Watch President's Speech | › President's Transcript

President Obama Outlines His Plan at Kennedy Space Center from SpaceRef on Vimeo.

NASA's Swift Catches 500th Gamma-ray Burst w/ Video Timeline

2010-04-19T19:50:00.002-04:00

This all-sky map shows the locations of Swift's 500 gamma-ray bursts, color coded by the year in which they occurred. In the background, an infrared image shows the location of our galaxy and its largest satellites.

In its first five years in orbit, NASA's Swift satellite has given astronomers more than they could have hoped for. Its discoveries range from a nearby nascent supernova to a blast so far away that it happened when our universe was only 5 percent of its present age. Swift primarily studies gamma-ray bursts (GRBs) -- the biggest and most mysterious explosions in the cosmos. On April 13, the spacecraft's "burst-o-meter" cataloged its 500th GRB.

"On the one hand, it's just a number, but on the other it is a remarkable milestone," said Neil Gehrels, Swift's lead researcher at Goddard Space Flight Center in Greenbelt, Md. "Each burst has turned over a new piece of the puzzle and a clearer picture is emerging."

"Over five years and 500 bursts, Swift has fulfilled every significant promise of its mission and, in addition, brought a wealth of surprises," noted Derek Fox, a Swift team member at Penn State in University Park, Pa.

Burst 500, officially known as GRB 100413B, exploded in constellation Cassiopeia as a long burst, a type usually associated with the death of a massive star. It wasn't detected in on-board analysis of data from the spacecraft's Burst Alert Telescope (BAT), which was interrupted 18 seconds after the burst as Swift slewed to a pre-planned target.

Instead, GRB 100413B came to light when David Palmer, an astrophysicist at Los Alamos National Laboratory in New Mexico, later analyzed the data. "The BAT team regularly digs through the data once it comes to the ground and finds weak bursts like this one that take a bit of special care," said Goddard's Judith Racusin, who coordinated burst observations that day.

Summaries of other notable bursts in Swift's storied career are listed below.

Swift's main job is to quickly localize each gamma-ray burst, report its position so that others can immediately conduct follow-up observations, and then study the burst using its X-ray and Ultraviolet/Optical telescopes. But it does much more, including ultraviolet studies of exploding stars, monitoring black holes and neutron stars for surges of high-energy radiation, and carrying out a long-term X-ray survey of the entire sky.

The spacecraft rocketed into orbit in November 2004. Managed by NASA's Goddard Space Flight Center, Swift was built and is operated in collaboration with Penn State, the Los Alamos National Laboratory in New Mexico, and General Dynamics of Gilbert, Ariz. Other partners include the University of Leicester and Mullard Space Science Laboratory in the United Kingdom, Brera Observatory and the Italian Space Agency in Italy, with additional collaborators in Germany and Japan.

Origins

Because gamma rays are the highest-energy form of light, the brief but brilliant blasts represent a colossal energy release. Gamma-ray bursts were discovered in 1967 by unclassified military satellites designed to look for clandestine nuclear tests. The first observations required extensive analysis to be sure that the bursts were truly originating beyond the solar system, and they weren't published until 1973.

Over the following years, astronomers learned that sufficiently sensitive instruments could detect about two bursts per day, on average, somewhere in the sky. Of those twice-daily GRBs, Swift's Burst Alert Telescope snares about one in eight for detailed study.

According to Lorella Angelini, a Goddard astrophysicist now developing a comprehensive burst database, the number of recorded GRBs is approaching 6,000. Yet if one considers only bursts with measured distances, Swift's share of the total is a whopping 75 percent.

An earlier NASA satellite, the Compton Gamma Ray Observatory, showed that bursts come in long and short varieties, with long bursts (those lasting longer than two seconds) outnumbering short bursts three to one. Compton also showed that bursts occur randomly and evenly over the sky. Maps of GRB distribution bear no hint of our galaxy's structure. This means that they are extremely far away — and all the more powerful.

Across the universe

A key breakthrough in understanding GRBs came from the Italian-Dutch satellite Beppo-SAX, which in 1997 provided the first precise burst positions. It later discovered lingering X-ray emission -- dubbed "afterglows" -- at burst locations. Observatories on the ground quickly discovered afterglows in visible light, which provided information that confirmed the burst's enormous distances. Astronomers now regularly study afterglows across the electromagnetic spectrum.

Most of the time, the hard task of measuring burst distances falls to ground-based observatories, which can target a burst's location with telescopes far larger than the Ultraviolet/Optical Telescope aboard Swift.

"Getting on the afterglows quickly with large ground-based telescopes remains a key element in understanding GRBs," said Fox, whose research focuses on follow-up observations. "It's this synergy between Swift and ground observatories that has really moved the ball forward, especially for short bursts."

And the farther the burst, the more important rapid ground follow-up becomes. At distances greater than about 12 billion light-years, gas clouds block ultraviolet wavelengths before they can reach Earth, and all optical light becomes shifted into infrared wavelengths only detectable by specially-equipped ground-based telescopes. Astronomers scramble to detect afterglow from new bursts as soon as they can.

"Thanks to such efforts, we know Swift has seen GRBs as close as about 100 million light-years and as far away as 13 billion light-years," adds Gehrels. Put another way, Swift sees gamma-ray bursts over a span of time equivalent to about 95 percent of the universe's age.

The long and the short of GRBs

By the time Swift launched, mounting evidence already pointed to the deaths of massive stars as the source of most long GRBs -- a scenario that still stands. When such a star runs out of fuel, its core collapses and likely forms a black hole surrounded by a dense hot disk of gas called an accretion disk. Somehow, the black hole diverts part of the infalling matter into a pair of high-energy jets that tear through the collapsing star.

The jets move so fast -- upwards of 99.9 percent the speed of light -- that collisions within them produce gamma rays. As the jet breaches the star's surface, a gamma-ray burst is born. The jet continues on, later striking gas beyond the star to produce afterglows.

Short bursts, however, proved much harder to pin down. "We didn't know their most basic properties," notes Ehud Nakar, an astrophysicist at Tel Aviv University in Israel. "We knew so little we weren't even sure that short GRBs were a unique astrophysical phenomenon."

It turns out they are. "Long GRBs originate from the collapse of stars just millions of years old, but the objects that give rise to some short GRBs reach ages of billions of years before exploding," Nakar adds.

The emerging picture is that short GRBs arise when two compact objects -- either a pair of neutron stars or a neutron star and a black hole -- collide and merge. These objects, which are the crushed cores of exploded stars, pack more mass than the sun into volumes just a few miles across. For those bound in a binary system, Einstein's relativity seals their fate.

According to Einstein, massive orbiting objects give off a type of energy called gravitational radiation. Although no one has yet detected these waves, astronomers have observed an effect predicted by this energy loss -- the slowly shrinking orbits of binary neutron stars. Over billions of years, the stellar cinders grow ever closer and finally merge in an event that unleashes titanic energies and creates a short GRB.

But Nakar thinks the full picture still eludes astronomers. "So far, the data favor merging neutron stars, and that is certainly the most popular idea, but other scenarios remain possible. We still do not know the origin of short GRBs."

Thanks mainly to burst identifications from Swift and the afterglow observations they make possible, scientists now have details on dozens of short bursts and their afterglows. "We're now beginning to understand the home galaxies of short GRBs," Fox said.

Over the past five years, Swift has delivered a great deal of revolutionary science. But its career isn't over yet -- and with a little luck, there will be much more to come.

Swift GRB highlights

April 13, 2010: NASA's Swift discovers its 500th burst. GRB 100413B is a long burst in the constellation Cassiopeia.

April 23, 2009: GRB 090423 in Leo holds the record for the farthest burst yet known -- 13.04 billion light-years away. "The burst is beyond the farthest confirmed galaxies and quasars, making it the most distant object we know in the universe today," Fox said. This find validates models suggesting that galaxy and star formation were well under way in the universe's first billion years and that some early stars died as bursts.

March 19, 2008: GRB 080319B, in Boötes, is truly extraordinary. It produces enough light to be seen briefly with the unaided eye, cresting at visual magnitude 5.3 despite occurring 7.5 billion light-years away -- or more than halfway across the visible universe. Scientists conclude that one of its particle jets appears to have been aimed squarely at Earth.

July 14, 2007: GRB 070714B explodes in Taurus. Afterglow observations indicate a distance of 7.3 billion light-years, making this one of the farthest short bursts to date.

Feb. 18, 2006: GRB 060218 explodes in Aries 450 million light-years away -- in our back yard, cosmically speaking. Although faint, the burst emits detectable gamma rays for more than 40 minutes and detectable optical and X-ray emission lasts more than 10 days. The event is a hybrid, showing characteristics of both a GRB and a supernova, and leads to the best observations yet exploring connections between these phenomena.

Sept. 4, 2005: At a distance of 12.77 billion light-years, GRB 050904, located in Pisces, is the farthest-known GRB at the time, the first of many such Swift records.

May 9, 2005: GRB 050509B, in Coma Berenices, erupts with a flash of gamma-rays that lasts just 0.03 second. Swift turns to the burst fast enough to detect 11 X-ray photons, making this the first short burst with a detected afterglow.

Dec. 17, 2004: Swift's first burst, in Crater, is eight-second-long GRB 041217.

Source: NASA/Goddard Space Flight Center

Craters Around Lunar Poles Could Be Electrified

2010-04-19T19:44:00.001-04:00

Illustration on LADEE probe in orbit around the Moon. More about Lunar Electric Craters

As the solar wind flows over natural obstructions on the moon, it may charge polar lunar craters to hundreds of volts, according to new calculations by NASA's Lunar Science Institute team.

Polar lunar craters are of interest because of resources, including water ice, which exist there. The moon's orientation to the sun keeps the bottoms of polar craters in permanent shadow, allowing temperatures there to plunge below minus 400 degrees Fahrenheit, cold enough to store volatile material like water for billions of years.

"However, our research suggests that, in addition to the wicked cold, explorers and robots at the bottoms of polar lunar craters may have to contend with a complex electrical environment as well, which can affect surface chemistry, static discharge, and dust cling," said William Farrell of NASA's Goddard Space Flight Center, Greenbelt, Md.

"This important work by Dr. Farrell and his team is further evidence that our view on the moon has changed dramatically in recent years," said Gregory Schmidt, deputy director of the NASA Lunar Science Institute at NASA's Ames Research Center, Moffett Field, Calif. "It has a dynamic and fascinating environment that we are only beginning to understand."

Solar wind inflow into craters can erode the surface, which affects recently discovered water molecules. Static discharge could short out sensitive equipment, while the sticky and extremely abrasive lunar dust could wear out spacesuits and may be hazardous if tracked inside spacecraft and inhaled over long periods.

The solar wind is a thin gas of electrically charged components of atoms - negatively charged electrons and positively charged ions - that is constantly blowing from the surface of the sun into space. Since the moon is only slightly tilted compared to the sun, the solar wind flows almost horizontally over the lunar surface at the poles and along the region where day transitions to night, called the terminator.

The researchers created computer simulations to discover what happens when the solar wind flows over the rims of polar craters. They discovered that in some ways, the solar wind behaves like wind on Earth - flowing into deep polar valleys and crater floors. Unlike wind on Earth, the dual electron-ion composition of the solar wind may create an unusual electric charge on the side of the mountain or crater wall; that is, on the inside of the rim directly below the solar wind flow.

Since electrons are over 1,000 times lighter than ions, the lighter electrons in the solar wind rush into a lunar crater or valley ahead of the heavy ions, creating a negatively charged region inside the crater. The ions eventually catch up, but rain into the crater at consistently lower concentrations than that of the electrons. This imbalance in the crater makes the inside walls and floor acquire a negative electric charge.

The calculations reveal that the electron/ion separation effect is most extreme on a crater's leeward edge - along the inside crater wall and at the crater floor nearest the solar wind flow. Along this inner edge, the heavy ions have the greatest difficulty getting to the surface. Compared to the electrons, they act like a tractor-trailer struggling to follow a motorcycle; they just can't make as sharp a turn over the mountain top as the electrons.

"The electrons build up an electron cloud on this leeward edge of the crater wall and floor, which can create an unusually large negative charge of a few hundred Volts relative to the dense solar wind flowing over the top," says Farrell.

The negative charge along this leeward edge won't build up indefinitely. Eventually, the attraction between the negatively charged region and positive ions in the solar wind will cause some other unusual electric current to flow.

The team believes one possible source for this current could be negatively charged dust that is repelled by the negatively charged surface, gets levitated and flows away from this highly charged region. "The Apollo astronauts in the orbiting Command Module saw faint rays on the lunar horizon during sunrise that might have been scattered light from electrically lofted dust," said Farrell.

"Additionally, the Apollo 17 mission landed at a site similar to a crater environment - the Taurus-Littrow valley. The Lunar Ejecta and Meteorite Experiment left by the Apollo 17 astronauts detected impacts from dust at terminator crossings where the solar wind is nearly-horizontal flowing, similar to the situation over polar craters."

Next steps for the team include more complex computer models. "We want to develop a fully three-dimensional model to examine the effects of solar wind expansion around the edges of a mountain. We now examine the vertical expansion, but we want to also know what happens horizontally," said Farrell. As early as 2012, NASA will launch the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission that will orbit the moon and could look for the dust flows predicted by the team's research.

Farrell is lead author of a paper on this research published March 24 in the Journal of Geophysical Research. The research is part of the Lunar Science Institute's Dynamic Response of the Environment at the moon (DREAM) project. The team includes researchers from NASA Goddard, the University of California, Berkeley, and the University of Maryland, Baltimore County.

Study Counters Clovis Comet Theory

2010-04-19T19:42:00.000-04:00

A team of researchers from the University of Arizona has revisited evidence pointing to a cataclysmic event thought by many scientists to have wiped out the North American megafauna - such as mammoths, saber tooth cats, giant ground sloths and Dire wolves - along with the Clovis hunter-gatherer culture some 13,000 years ago.

The team obtained their findings following an unusual, multidisciplinary approach and published them in the Proceedings of the National Academy of Sciences (PNAS).

"The idea of an extraterrestrial impact driving the Pleistocene extinction event has recently caused a stir in the scientific community," said C. Vance Haynes, a professor emeritus at UA's School of Anthropology and the department of geosciences, who is the study's lead author. "We systematically revisited the evidence for an impact scenario and discovered it just does not hold up."

Haynes has dedicated his scientific career to the study of the Clovis people - the first well-defined culture in the New World - and discovered many sites with evidence of their presence in Arizona.

One of the most prominent and most studied of those sites is the Murray Springs Clovis site in southeastern Arizona, where archaeologists and anthropologists have unearthed hundreds of artifacts such as arrowheads, spear points and stone tools.

The site includes the remains of a Clovis hunters' camp close to a mammoth and a bison kill site, allowing the researchers to reconstruct the daily life of the Clovis culture to a certain extent.

When the last ice age came to an end approximately 13,000 years ago and the glaciers covering a large portion of the North American continent began melting and retreating toward the north, a sudden cooling period known as the "Big Freeze" or, more scientifically, the Younger Dryas, reversed the warming process and caused glaciers to expand again.

Even though this cooling period lasted only for 1,300 years, a blink of an eye in geologic timeframes, it witnessed the disappearance of an entire fauna of large mammals.

The big question, according to Haynes, is 'Why did those animals go extinct in a very short geological timeframe?'"

"When you go out and look at the sediments deposited during that time, you see this black layer we call the Black Mat. It contains the fossilized remains of a massive algae bloom, indicating a short period of water table rise and cool climate that kept the moisture in the soil. Below the Black Mat, you find all kinds of fossils from mammoths, bison, mastodons, Dire wolves and so forth, but when you look right above it - nothing."

Scientists have suggested several scenarios to account for the rapid Pleistocene extinction event. Some ascribe it to the rapid shift toward a cooler and dryer during the "Big Freeze," causing widespread droughts.

Haynes disagrees. "We find evidence of big changes in climate throughout the geologic record that were not associated with widespread extinctions."

Others have blamed the demise of the North American megafauna on pathogens brought onto the North American continent by animals from the Old World crossing the Bering Strait.

"The disease hypothesis does not hold up well in the light of natural selection and evolution," Haynes said, "because some individuals would have been immune to the pathogens and survived."

The two attempts to account for the mass extinction event prevailing at this point include humans and celestial bodies. Many deem it possible that humans such as the Clovis culture hunted the Pleistocene mammals to extinction, as proposed by UA Professor Emeritus Paul S. Martin.

Alternatively, it is thought that a comet or asteroid slammed into the glaciers covering the Great Lakes area, unleashing firestorms that consumed large portions of vegetation. In addition, the dust and molten rock kicked up high into the atmosphere during the impact could have shrouded the Earth in a nuclear winter-like blanket of airborne dust, blocking sunlight and causing temperatures to plummet.

In the present study, Haynes and his coworkers set out to put the evidence for an impact scenario to the test: Unusually high concentrations of spherical magnetic particles in the soil samples taken at the Murray Springs Clovis site had been interpreted as indication of an extraterrestrial source.

Another hint in this direction was a spike in the Black Mat's iridium content - an element rarely encountered on Earth but quite abundant in meteorites. In addition, the occurrence of nanodiamonds had been suggested as evidence of an extraterrestrial origin. Finally, a supposedly abundant charcoal content in the soil samples had been cited as evidence of widespread wildfires ravaging the land in the aftermath of the impact.

To ensure their samples were comparable, Haynes collected at the same locations in the Black Mat layer as the team proposing the impact scenario: "I sampled where they sampled and at the same times they sampled."

Using highly sensitive and sophisticated analytical methods, Haynes' coworkers at the department of geosciences and UA's Lunar and Planetary Lab then analyzed their samples for the evidence that had been presented in support of the impact scenario.

The team did find abundant magnetic spherules. But where did they come from? Was a meteorite the only possible source?

"Researchers have only begun to study those magnetic spherules recently, so we still don't know much about them," Haynes said. "What we do know is that they occur in exhaust from vehicles and power plants."

To determine whether the magnetic spherules found at Murray Springs could be of terrestrial origin, Haynes followed a tip from UA Geosciences Professor Anthony Jull, who suggested taking a sample of dirt from the rooftop of his house and examining it under the microscope.

Haynes remembers looking at the soil samples on a microscope slide, and "sure enough, there they were - among all the dust and grains and grit

"We did confirm the other authors' findings that the magnetic spherules are concentrated in the samples at the Clovis site, but when you study the topography on which the sediments were laid down, you immediately see why: Rainwater washed them down into a river bed, where they accumulated over time. Since this is where the samples with the increased spherule content came from, we were not surprised to find more of the spherules there. The samples we took from the slopes do not have higher than normal concentrations of spherules."

What about the charcoal indicating vegetation burning?

"The only places we found charcoal were the campsites of the Clovis people, where they build their fires."

But where could the nanodiamonds come from?

Again, Haynes' colleague, Anthony Jull, had the answer. A common ingredient of cosmic dust, nanodiamonds are constantly raining down onto the earth's surface, rendering them unsuitable as unequivocal evidence of an extraterrestrial impact. "Something happened 13,000 years ago that we do not understand," said Haynes. "What we can say, though, is that all of the evidence put forth in support of the impact scenario can be sufficiently explained by earthly causes such as climate change, overhunting or a combination of both."

Does this mean the results obtained by Haynes and his coworkers rule out the possibility of a cosmic event?

"No, it doesn't," Haynes said. "It just doesn't make it very likely."

ISRO To launch Cartosat-2B On May 9

2010-04-19T19:40:00.001-04:00

Undeterred by the GSLV-D3 mission failure, India is going ahead with the launch of an advanced remote-sensing satellite Cartosat-2B, now tentatively fixed for May 9 from Sriharikota spaceport.

The high-resolution spacecraft, designed for an operational life of five years, is slated to be launched from the first launchpad on May 9 around 10 am, ISRO spokesperson S Satish told said here on Friday.

Thursday's GSLV-D3 mission to flight-test the indigenous cryogenic engine and stage for the first time ended in failure after the rocket veered off course and plunged into the sea.

GSLV and PSLV missions are independent of each other. ISRO officials said there is no change in its earlier announced plans to launch PSLV in the first half of May - now fixed for May nine.

"It (Cartosat-2B) will give pictures of 0.8 metre resolution," ISRO chairman K Radhakrishnan has said. In simple terms, the single panchromatic camera on board this cartographic satellite would be able to identify and take pictures of a moving car.

Thus, this highly-agile satellite, weighing around 690 kg, is expected to give a boost to the tasks of infrastructure and urban planning. The camera provides scene specific spot imageries for cartographic and a host of other civilian applications.

Dual Drill Designed For Europa Ice Mission

2010-04-17T23:22:00.000-04:00

A mole-like thermal drill designed to cut through the icy surface of Jupiter's moon Europa could be on a future mission slated for launch in 2020. Such a device would represent the best of both worlds by using heat to melt through the ice and rotating drill blades to clear away rocky material. The drill would be nestled inside a larger penetrator probe that would burrow itself into Europa's icy shell.

"Penetrators are the most feasible, cheapest and safest option for a landing on Europa today, and the knowledge to build those is there," said Peter Weiss, a post-doc now at the National Center for Scientific Research (CNRS) in France. He and his colleagues at the Hong Kong Polytechnic University worked with other researchers at the Institut fuer Weltraumforschung in Graz, Austria on a study detailed in the January issue of the journal Advances in Space Research.

NASA and the European Space Agency (ESA) have teamed up on the Europa Jupiter System Mission (EJSM), with both Russia and Japan also showing interest. The mission could be composed of several orbiters peering down at Europa, but Russia has its eyes on a possible lander - and the Russians have already built penetrators for past missions, such as the failed Mars 96 mission.

"A thermal drill could be the 'nose' of a penetrator, to taste the ice of Europa," Weiss explained.

Drilling gets hot
Any landing probe that wants to search for signs of life on Europa must go deeper than two meters into the surface ice, because heavy radiation and particle bombardment would have erased any biological traces in the top layer.

Having a robotic lander make a soft landing before preparing to drill would be a more complicated and expensive task compared to a penetrator, Weiss said. A thermal drill could simply deploy from the side of the penetrator after impact, and begin drilling through the pristine ice below to sample material at depths of up to 10 meters.

Estimates for the thickness of Europa's ice shell vary between a few kilometers and tens of kilometers, but Weiss says it doesn't make sense to go much deeper than 10 meters because of the current state of technology. For instance, the drill would be tethered to the penetrator by a communication cable, and the length of cable would be limited based on how much the probe could carry.

This cable would allow data collected from the drill to snake back to the main scientific instruments in the penetrator, and then the data would get beamed up to an orbiter.

Lab experiments showed how a thermal drill design fared much better in dealing with the combined challenge of ice and regolith, as opposed to a melting probe such as the Cryobot that relies upon heat alone.

Inner pressure inside the hole is expected to increase and allow for liquid water once the initial borehole has refrozen. That would allow the drill to sample water by using a micro-pump, but the refreezing hole would also protect the pristine ice against possible contamination from the outside.

Forget the submersibles
Some concepts of a submersible exploring the supposed ocean depths of Europa have appeared in past years, and NASA has tested robotic subs in the frigid lakes of Antarctica.

But Weiss, who draws upon several years working with sub-sea robotics, said that current technology cannot deploy a submersible on Europa. Just packing in all the cabling that would connect a submersible to the main landing craft would represent a problem. While the ice shell is thought to be at least several kilometers thick, no one knows exactly how far down the ocean may be - there could be a thick layer of slush between the ice shell and ocean. Another question is the distance down to the ocean floor.

"The ocean beneath - if existent - could be 100 kilometers deep," said Weiss.

Robotic subs on Earth have reached ocean depths of 11 km (6.8 miles), but weighed several tons and required huge surface support ships. That doesn't work for a mission to Europa that needs to travel light.

"Institutes that pretend to develop sub-sea robots 'to explore the bottom of Europa's ocean' should be financed by Hollywood, not NASA," Weiss said.

Waiting for a call
The researchers have so far tested their drill in both pressure and vacuum environments, but still want to boost its efficiency. A next logical step might test how well a thermal drill survives impact aboard a penetrator.

Whether or not a thermal drill or any sort of landing probe gets a shot at Europa's icy surface remains up in the air. But even as the different space agencies figure out their roles and budgets, Weiss says there's a sense of urgency to find out what's going on with Europa.

A mission that consisted of only orbiters might find more interesting evidence that supports the possibility of life on the Jovian moon, but would not have the ability to go down and find proof. And a follow-up mission might not even launch until the 2040s - good reason for the current generation of scientists to want some surface explorer element.

"Otherwise, we won't have any confirmation on astrobiology on Europa - or maybe even in the solar system - during our lifetime," Weiss said.

Shuttle Discovery leaves space station, heads for Earth

2010-04-17T23:20:00.000-04:00

Astronauts aboard the space shuttle Discovery embarked Saturday on their journey back to Earth after undocking from the International Space Station (ISS), NASA said.

The shuttle, after its delicate detachment from the outpost at 8:52 am (1252 GMT), completed an over 90-minute fly around of the station to take photos of the complex before heading on its deorbit flight path, the US space agency said on its website.

The crew will end their 14-day mission on Monday, officials said, with an expected landing at Kennedy Space Center in Cape Canaveral, Florida at 8:51 am (1251 GMT).

It has been a landmark mission in space exploration in a number of different ways: the first shuttle trip with three female crew members, who joined four male astronauts on the flight, and when they arrived at the ISS, it was the first time four women were in orbit at the same time.

The mission also marked the first time there were two Japanese astronauts in space at once, with Discovery mission specialist Naoko Yamazaki joining Soichi Noguchi of the Japan Aerospace Exploration Agency, who arrived at the station on December 22.

Discovery and its crew delivered nearly eight tonnes of cargo, including spare bunks for the occupants of the space station, a large tank of ammonia coolant and seven racks filled with science experiments.

Among the gear hauled into space was a freezer to preserve samples of blood, urine, saliva, plants or microbes used in micro-gravity experiments for later analysis back on Earth.

The shuttle also brought up to the ISS an exercise machine designed to study the effects of weightlessness on the body's musculoskeletal system. Muscles can atrophy during long sojourns in space so astronauts have to exercise regularly.

During the shuttle's stay at the orbiting outpost, US President Barack Obama visited Kennedy Space Center to set a bold new course for the future of space travel ahead of the 30-year-shuttle fleet's retirement at the end of this year.

Among the goals set for the US space effort, Obama on Thursday announced plans to send US astronauts into the orbit of Mars within the next three decades.

He also sought to quell a storm of outrage caused by earlier administration plans, vowing before NASA staff that he was "100 percent committed" to their mission and to the future of the US space agency.

"I believe that space exploration is not a luxury, it's not an afterthought in America's quest for a brighter future. It is an essential part of that quest," he said.

Just three more space flights remain for shuttles Atlantis, Discovery and Endeavour, with a launch to the ISS in September scheduled to be the last of 134 total flights for the program before the three remaining orbiters are retired. The first shuttle flew in April 1981.

After the shuttle fleet is grounded, US astronauts will be left to hitch rides on Russian spacecraft to the orbiting station until a replacement program is developed.

The ISS, which orbits 220 miles (350 kilometers) above Earth, is a 100-billion-dollar project begun in 1998 with the participation of 16 countries, financed mainly by the United States.

HiRISE images for April 14, 2010

2010-04-17T00:44:00.001-04:00

The following new captioned and spotlight images taken by the High Resolution Imaging Science Experiment (HiRISE) on the Mars Reconnaissance Orbiter spacecraft are now available:

New Impact Crater
This small crater (approximately 7 meters, or 20 feet, in diameter) was created sometime within the last five years. We know this because we have enough images of Mars over the last decade that we can narrow down its formation date using "before" images where the crater did not appear.
Comic and Tragic Craters
The subimage shows two craters on Mars that are reminiscent of the Greek muses of comedy and tragedy.
Gully Grab Bag in Crater Wall, Terra Sirenum Region
This observation shows the complex, gullied western wall of a kilometer-deep impact crater in the Terra Sirenum region.
Scalloped Topography in Peneus Patera Crater
This image, near the southeast rim of Peneus Patera crater, is marked by depressions in the mantle with scalloped edges.
Layers Exposed on Slope in Echus Chasma Region
The layers seen in this HiRISE subimage of Echus Chasma are very different from the light-toned, thinly bedded layers HiRISE has observed in deposits seen elsewhere in Valles Marineris.

New Insight into How Neutron Stars Cool

2010-04-17T00:39:00.002-04:00

Image comment: Image showing the Cassiopeia A supernova remnant. Inset depicts the neutron star at its core
Image credits: Image: NASA / CXC / Southampton / W. Ho et al. Illustration: NASA / CXC / M.Weiss

Using telescope data spanning an entire decade, researchers have recently compiled a new dataset on how the renowned supernova remnant Cassiopeia A's neutron star is evolving over time. The celestial body is the youngest known such formation to date, and so peering into the interior of this super-dense star is something that astronomers are very keen on doing. Details of the long-term study were presented Thursday, April 15, at the RAS National Astronomy Meeting, held in Glasgow, Scotland, PhysOrg reports.

The presentation was made by University of Southampton astronomer Dr Wynn Ho and colleague Dr Craig Heinke, who is based at the University of Alberta, in Canada. The team used images collected between 2000 and 2009, using the NASA Chandra X-Ray Observatory, one of the American space agency's four Great Observatories. “This is the first time that astronomers have been able to watch a young neutron star cool steadily over time. Chandra has given us a snapshot of the temperature roughly every two years for the past decade and we have seen the temperature drop during that time by about 3 [percent],” Dr Ho told colleagues gathered at the meeting.

Neutron stars are the collapsed cores of former massive stars that did not have sufficient mass or did not experience the necessary conditions to become a black hole. They are composed of considerable amounts of elementary particles called neutrons, which are compressed together by the force of gravity at unimaginably-high pressures. This means that the matter at their cores has a density that is trillions of times higher than that of lead. Generally, astrophysicists say that neutron stars are produced following supernova explosions. In the case of Cassiopeia A, the explosion is thought to have occurred around the year 1680.

Scientists believe that the remnant core was initially heated up to billions of degrees Celsius, but add that today it only has a temperature of around two million degrees. ”Young neutron stars cool through the emission of high-energy neutrinos – particles similar to photons but which do not interact much with normal matter and therefore are very difficult to detect. Since most of the neutrinos are produced deep inside the star, we can use the observed temperature changes to probe what’s going on in the neutron star’s core,” Ho added.

“ The structure of neutron stars determines how they cool, so this discovery will allow us to understand better what neutron stars are made of. Our observations of temperature variations already rule out some models for this cooling and has given us insights into the properties of matter that cannot be studied in laboratories on Earth,” he further explained. A paper detailing the study was submitted to the esteemed publication Astrophysical Journal.

New Technique Can Spot Smaller Exoplanets

2010-04-17T00:36:00.000-04:00

Image comment: This image of the planets in the HR8799 system were found using vortex coronagraph
Image credits: NASA / JPL-Caltech / Palomar Observatory

Up until now, methods of detecting exoplanets beyond our solar system could only see space rocks that were very large, and also fairly far away from their parent stars. These limitations occur on account of the fact that the brightness of exoplanets can rarely be observed directly, due to the light the stars they orbit emit. This means that small planets, about the size of Earth, can only be detected with incredible difficulties. However, this class of celestial objects is thought to be the most likely to support alien life. Now, a new observations technology could surpass the previous limitations.

According to the investigators behind the new method, the technique is especially suitable for detecting small exoplanets, that orbit their parent star closer to, or even within, their respective habitable zones. The method can also detect these bodies at larger distances from our solar system than ever before, which could significantly increase the chances of astronomers finding planets that have temperatures suitable for maintaining liquid water on their surface. Experts plan to find these objects using a small instrument called a “vortex coronagraph.”

Unlike other detection methods, which rely on the use of impressively-large telescopes, this device only uses a small portion of an observatory. In a demonstrative study, the technique was used on the 1.5-meter (5-foot) Hale Telescope, located at the Palomar Observatory, in San Diego. The study team, led by NASA Jet Propulsion Laboratory (JPL) expert Gene Serabyn, managed to find three already-discovered planets using this small telescope. The space rocks orbit the star called HR 8799, and they are all gas giants similar to Jupiter, though more massive.

Initially, these bodies were found using the Mauna Kea, Hawaii-based 10-meter (33-foot) telescopes of the W.M. Keck Observatory, and the 8.0-meter (26-foot) Gemini North Observatory. “We managed to see these planets with a telescope that's smaller than one panel on the Keck telescope. What this [vortex coronagraphy] does is it allows you to consider using a much smaller telescope, and something that's much more affordable, to look for Earth-like planets,” the JPL expert tells Space. Details of how the device works can be found in the April 15 issue of the esteemed scientific publication Nature.

Cassini Images First Extraterrestrial Lightnings

2010-04-17T00:34:00.001-04:00

Image comment: This image from NASA's Cassini spacecraft -- the first of its kind -- shows lightning on Saturn's night side flashing in a cloud that is illuminated by light from Saturn's rings
Image credits: NASA / JPL-Caltech / Space Science Institute / University of Iowa

The NASA Cassini spacecraft can add another world first to its already-impressive tally of accomplishment. Scientists at the Pasadena, California-based NASA Jet Propulsion Laboratory (JPL) announce that the orbiter is the first probe ever to image lightning strikes on another planet. The explorations robot has been orbiting the gas giant Saturn since July 1, 2004, and it has already sent back exquisite and outstanding images of the planet, its moons and its intricate ring system.

With the newly-received data, investigators at NASA were able to piece together the first short video clip of lightning discharges on another planet. In addition to the video components, the film is also completed by the crackle of radio waves, which Cassini's sensitive instruments detected when the electrical discharges took place.

“This is the first time we have the visible lightning flash together with the radio data. Now that the radio and visible light data line up, we know for sure we are seeing powerful lightning storms,” says Space Research Institute radio and plasma wave science team associate member, Georg Fischer. The facility is located in the city of Graz, Austria.

“What's interesting is that the storms are as powerful – or even more powerful – at Saturn as on Earth. But they occur much less frequently, with usually only one happening on the planet at any given time, though it can last for months,” adds Cassini imaging science subsystem team member Andrew Ingersoll. The expert is based at the California Institute of Technology (Caltech), which houses and manages the JPL.

“The visible-light images tell us a lot about the lightning. Now we can begin to measure how powerful these storms are, where they form in the cloud layer and how the optical intensity relates to the total energy of the thunderstorms,” concludes Caltech expert Ulyana Dyudina, who was the first person to see the lightnings on Saturn. He is also an associate of the Cassini imaging team. Details of the discovery have already been accepted for publication in an upcoming issue of the esteemed scientific journal Geophysical Research Letters.

The Cassini-Huygens mission was a cooperative project of NASA, the European Space Agency (ESA) and the Italian Space Agency (ASI). The JPL manages the Cassini-Huygens mission for NASA Science Mission Directorate, at the agency's Headquarters in Washington DC. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The Huygens mission landed successfully on Titan in January, 2005, and began relaying data from the surface. Though never designed to serve as a lander, the instrument continued to send signals for about 90 minutes after impact.

No Peep From Phoenix In Third Odyssey Listening Stint

2010-04-17T00:32:00.000-04:00

NASA's Mars Odyssey orbiter heard no signal from the Phoenix Mars Lander when it listened from orbit while passing over Phoenix 60 times last week.

Odyssey had also listened for a signal from Phoenix during periods in January and February. During the third campaign, April 5 through April 9, the sun stayed above the horizon continuously at the arctic site where Phoenix completed its mission in 2008.

The solar-powered lander examined ice, soil and atmosphere at the site for two months longer than its planned three-month mission before succumbing to seasonal decline in sunlight. It was not designed to withstand winter conditions.

However, in case it did, NASA has used Odyssey to listen for the signals that Phoenix would have transmitted if abundant spring sunshine revived the lander.

"In the unlikely event that Phoenix had survived the harsh Martian arctic winter and been able to achieve a power-positive state with the return of continuous sunshine, there is a very high likelihood that one or more of these 60 overflights would have overlapped with a transmission attempt by the lander," said Chad Edwards, chief telecommunications engineer for the Mars Exploration Program at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

"This was the last of our three planned Phoenix search campaigns. The Mars program will evaluate the results in hand to assess whether further action is warranted," Edwards said.

Picking Up Pace To Endeavour Crater

2010-04-17T00:29:00.000-04:00

Endeavour crater will be the final destination for Opporitnity.

Opportunity has picked up the pace a little as she presses on toward Endeavour crater, recharging her batteries between drives.

First, the rover must clear a region of large ripples, so Opportunity is heading south before the turn to the East. Sols 2206 (April 8, 2010) and 2208 (April 10, 2010), each saw a roughly 50-meter (164-foot) drive straight south.

On Sol 2211 (April 13, 2010), Opportunity drove 30 meters (98 feet) east, deliberately crossing a series of ripples to collect terrain data that will be used to calibrate simulation software. That software will help design future drives.

The right-front and right-middle wheel are exhibiting modestly elevated motor current levels, which the project continues to watch. The plan ahead is more driving. As of Sol 2211 (April 13, 2010), the solar array energy production was 227 watt-hours with an atmospheric opacity (tau) of 0.347 and a dust factor of 0.474.

Total odometry is 20,385.31 meters (20.39 kilometers, or 12.67 miles).

Japanese astronaut solves bubble puzzle

2010-04-17T00:28:00.000-04:00

Of all the experiments Japanese astronaut Naoko Yamazaki has carried out in space -- making sushi in a kimono and playing a harp -- blowing soap bubbles has arguably brought the biggest breakthrough.

Yamazaki, Japan's second female astronaut and its first mum-in-space, is part of the crew that joined a team on the International Space Station (ISS) last week in the latest mission for US space shuttle Discovery.

The trip put more women in orbit than ever before on a mission to deliver nearly eight tonnes of cargo, including spare bunks for the space station occupants, a tank of ammonia coolant and scientific instruments.

But mission specialist Yamazaki had her own agenda after promising her daughter she would solve a mystery puzzling the sharp-minded seven-year-old: why coloured bubblebath makes colourless soap bubbles in water.

Yamazaki on Wednesday mixed red tropical fruit juice with soap and blew shiny red bubbles in space to the delight of her daughter Yuki, who watched with the astronaut's husband Taichi on a video phone, Jiji Press said.

The experiment worked because space's zero-gravity environment allowed colour pigments to spread evenly around a bubble, said Yamazaki's husband.

The latest experiment follows a tradition of Japanese astronauts testing left-field ideas in space, ranging from trying out a flying carpet to applications of eye drops.

Celebrating The ISS And Preparing For The Future

2010-04-17T00:27:00.000-04:00

Now that the International Space Station is fully operational, the programme partners will gather in Berlin on 19-21 April to discuss the successes and potential of this unique international cooperation.

The International Space Station (ISS) is now almost complete and capable of housing a crew of six astronauts. At times, more than 12 people can work aboard.

One of the most ambitious international projects ever and the largest spacecraft to orbit our planet is ready for at least 10 more years of productive operations.

The Station's success stories will be presented during a three-day symposium at the Hotel Adlon Kempinski in Berlin beginning 19 April. International speakers will discuss their achievements, the lessons learnt and current projects. The gathering has been convened by ESA Director of Human Spaceflight, Simonetta Di Pippo, on behalf of the ISS international partners.

The speakers of the symposium will include several astronauts, high-level representatives of the participating space agencies and major players from the industry. The keynote speaker on the first day is Nobel Prize laureate Prof. Samuel Ting. Prof Ting is leader of the Alpha Magnetic Spectrometer (AMS), a cosmology experiment for capturing the cosmic ray particles for better understanding of the origins of the Universe and the biggest scientific experiment designed for the ISS. Professor Ting will speak about a subject close to his research: the value of the ISS for science.

The first expedition crew, William Shepherd, Yuri Gidzenko and Sergei Krikalev, who opened a new era in international cooperation by moving into the Station 10 years ago, will also reunite, for the first time, during the symposium.

'ISS for you: citizens first'

The slogan of the symposium reflects the importance of the International Space Station to humankind in general. It is this century's first concrete example of peaceful cooperation, uniting 14 nations.

Benefiting from uninterrupted weightlessness and a privileged vantage point on Earth, the Universe and the space environment, its research facilities cover a wide range of fundamental and applied fields, affecting our daily lives on Earth. It is also a unique testbed to prepare advanced concepts for future exploration missions.

ISS is a classroom in space, inspiring new generations. From it, we can see the fragility of our home planet and the vastness of the Universe. It is at the final frontier, inviting us to explore, learn and use.

As the symposium will show, the Station is benefiting us all.

First Data from CryoSat-2 Successfully Received

2010-04-13T13:52:00.000-04:00

Image comment: The CryoSat mission is dedicated to monitoring of the changes in the thickness of marine ice floating in the polar oceans and thickness variations on the ice sheets that overlay Greenland and Antarctica.

Image credits: ESA / AOES Medialab

Experts at the European Space Agency (ESA) announce that one of their control centers has already begun receiving the first datasets from the newly-launched CryoSat-2 satellite. The instrument took off from the Baikonur Cosmodrome, in Kazakhstan, on April 8, and its managers say that it has performed beautifully during the critical stage of the mission. In most satellite launches, the first few days of operations are absolutely critical. Just hours after mission experts turned on the sophisticated radars aboard the spacecraft, they began receiving back telemetry, the ESA team says.

Only a few minutes after being launched last Thursday, the satellite was inserted by its Dnepr delivery system into a polar orbit above Earth. For the next three days, researchers working from the European Space Operations Center (ESOC), in Germany, monitored the payload and health status of the satellite around the clock. The goal was to ensure that everything was fairing along nicely and that no damage had come to either the satellite or its cargo during the harsh conditions of lift-off.

“The satellite is in excellent condition and the mission operations team quickly resolved the few problems that came up. It's been a very smooth entry into orbit, precisely as planned,” said on April 11 Pier Paolo Emanuelli, the Flight Director of ESA. He also announced at the time that the Launch and Early Orbit Phase (LEOP) of the mission had concluded successfully. The main instrument on CryoSat-2, called the Synthetic Aperture Interferometric Radar Altimeter (SIRAL), was turned on late Sunday, and it immediately began picking up echo data from the ground.

The ESA Kiruna ground station picked up on the spacecraft's telemetry shortly afterwards. The first data were collected and processed on-site, before being shipped out to ESA. “We switched SIRAL on and it worked beautifully from the very start. Our first data were taken over the Antarctic's Ross Ice Shelf, and clearly show the ice cover and reflections from underlying layers. These are excellent results at such an early stage and are a tribute to the hard work of the entire CryoSat community,” said the lead investigator of the CryoSat-2 mission, professor Duncan Wingham.

“The combined ground teams proved the value of months of extensive training and preparation and the satellite has shown to be a high-quality machine with very few problems. The launch and orbit injection have been almost flawless and we are looking forward to an extremely productive mission,” concluded the ESA project manager for the mission, Richard Francis.

Third STS-131 Spacewalk Completed

2010-04-13T13:48:00.000-04:00

Image comment: STS-131 astronauts are seen here as they were trying to affix an old ammonia tank to the payload bay of space shuttle Discovery

Image credits: NASA TV

Earlier today, two STS-131 mission specialists stepped out of the International Space Station's (ISS) Quest airlock, to conduct the third and final spacewalk in their schedule. NASA astronauts Rick Mastracchio and Clayton Anderson each performed the sixth extra-vehicular activity (EVA) of their careers, and they managed to successfully complete all the major chores allotted to them. They successfully replaced a large, old ammonia tank on the outer hull of the ISS with a new one and then deposited the old one back into the payload bay of space shuttle Discovery.

Their sortie began at 2:14 am (0614 GMT) and was originally programmed to last for about six and a half hours. However, the two hit an obstacle in their efforts when Mission Control announced them that one of the valves on the four hoses they had just installed appeared to be stuck. The hoses transport liquid ammonia coolant to the tank and are essential for maintaining proper temperature levels on the ISS. As experts on the ground struggled to fix the glitch on their end, Mastracchio and Anderson had their own problems with installing the old ammonia tank in the orbiter's payload.

A stubborn bolt gave them some trouble, which was nothing new. In the previous two STS-131 EVA, the astronauts encountered other instances in which bolts would not budge. They needed to use prybars and even brute force at times to get them loose. This instance was different in the sense that the small metal piece was misaligned. Therefore, the two astronauts needed to unscrew another bolt, align the entire plate properly, and then affix them all back into place. After they completed this chore, they removed some unneeded aluminum coverings from the outer hull of the orbital facility. This task was originally planned for their second EVA, but delays made them leave this job for today.

“We have two roll-over tasks that were originally planned as part of [the second spacewalk] that are going to be added to the front end. After they do that, they'll go on and essentially proceed with the remainder of [the third spacewalk], in large part what was planned pre-flight,” explained Mike Sarafin, the Lead Shuttle Flight Director at NASA. As the astronauts were working outside, their colleagues inside the ISS continued the task of unloading some of the 17,000 pounds (7,711 kilograms) of supplies from the newly-arrived MPLM (Multi-Purpose Logistics Module) Leonardo. Completely unloading the container will take a few more days, NASA officials announce, quoted by Space.

M81's 'Halo' Sheds Light on Galaxy Formation

2010-04-13T07:45:00.001-04:00

Visible light image of spiral galaxy M81 taken by Suprime-Cam.

Observations with Subaru Telescope's Prime Focus Camera (Suprime-Cam) have revealed an extended structure of the spiral galaxy Messier 81 (M81) that may hold a key to understanding the formation of galaxies. This structure could be M81's halo. Until now, ground-based telescopes have only observed individual stars in the haloes around the Milky Way and Andromeda Galaxies. Differences in M81's extended structure from the Milky Way's halo may point to variations in the formation histories of spiral galaxies.

M81 is one of the largest galaxies in the M81 Group, a group of 34 galaxies located toward the constellation Ursa Major. At 11.7 million light years from Earth, it is one of the closest groups to the Local group, the group of galaxies that includes our own Milky Way. Thanks to its proximity and similarity to the Milky Way, M81 provides an excellent laboratory for testing galaxy formation models.

The most prominent of these models predicts that galaxies are built up from the merging and accretion of many smaller galaxies that orbit within their gravitational sphere of influence. This chaotic, bottom-up growth leaves behind a halo of stars around massive spirals like the Milky Way. Do the findings about M81's extended structure, possibly its halo, support this view?

True to its promise as an effective tool for the study of galaxy evolution, Subaru's telescope has provided data to address this question. The enormous light-gathering power of Subaru Telescopes's 8.2 meter primary mirror and the wide field-of-view of its Suprime-Cam enabled the telescope to provide evidence for a faint, extended structural component beyond M81's bright optical disk. It probed into space over one-hundred times darker than the night sky and imperceptible to the naked eye. The telescope spotted individual stars and gathered enough of them to identify M81's extended component and analyze its physical properties.

The results defy exact classification of the extended structure as a halo. Although the spatial distribution of its stars resembles the Milky Way's halo, M81's "halo" differs from the Milky Way's in other respects. Measurements of the total light from all of its stars and analysis of their colors point to estimates that M81's "halo" could be several times brighter and contain more processed materials, nearly twice as much mass in the form of metals (all elements heavier than helium), than the Milky Way's halo.

These differences prompt some fascinating questions. Do we need to expand our definition of a halo? Does this structure have a very different formation history than the Milky Way's halo? Did these differences arise because M81 cannibalized more or different kinds of small galaxies in the past than the Milky Way did? Regardless of the answers to these queries, the results of this research contribute to the growing body of evidence that the outer structures of apparently similar galaxies are much more important and complex than astronomers have previously thought.

Provided by Subaru Telescope

Cassini Finishes Saturnian Doubleheader

2010-04-12T20:02:00.000-04:00

This image was taken on April 7, 2010 by NASA's Cassini spacecraft. The camera was pointing at Saturn. But, by appropriate orientation of the spacecraft, the cameras were able to capture Dione in the sights. Image Credit: NASA/JPL/Space Science Institute

NASA's Cassini spacecraft completed its double flyby this week, swinging by Saturn's moons Titan and Dione with no maneuver in between. The spacecraft has beamed back stunning raw images of fractured terrain and craters big and small on Dione, a moon that had only been visited once before by Cassini.

The Titan flyby took place April 5, and the Dione flyby took place April 7 in the UTC time zone, and April 6 Pacific time. During the Titan flyby, an unexpected autonomous reset occurred and Cassini obtained fewer images of Titan than expected. But the cameras were reset before reaching Dione, which was the primary target on this double flyby.

Scientists are poring over data from Dione to discern whether the moon could be a source of charged particles to the environment around Saturn and material to one of its rings. They are also trying to understand the history of dark material found on Dione.

A fortuitous alignment of these moons allowed Cassini to attempt this doubleheader. Cassini had made three previous double flybys and another two are planned in the years ahead. The mission is nearing the end of its first extension, known as the Equinox Mission. It will begin its second mission extension, known as the Solstice Mission, in October 2010.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate in Washington. The Cassini orbiter was designed, developed and assembled at JPL.

More information about the Titan flyby, dubbed "T67," is available at: http://saturn.jpl.nasa.gov/mission/flybys/titan20100405/.

More information about the Dione flyby, dubbed "D2," is available at: http://saturn.jpl.nasa.gov/mission/flybys/dione20100407/.

Space Telescope Moves on with One Detector

2010-04-12T19:59:00.002-04:00

Mission engineers and scientists with NASA's Galaxy Evolution Explorer, a space telescope that has been beaming back pictures of galaxies for three times its design lifespan, are no longer planning science observations around one of its two ultraviolet detectors.

"The remaining, near-ultraviolet detector is still busy probing galaxies both nearby and distant," said Kerry Erickson, the mission's project manager at NASA's Jet Propulsion Laboratory in Pasadena. "We've got lots of science data coming down from space."

The Galaxy Evolution Explorer rocketed into space from a jet aircraft in 2003. For four years of its primary mission, it mapped tens of millions of galaxies across the sky in ultraviolet light, some as far back as 10 billion years in cosmic time. Its extended mission began in 2008, allowing it to probe deeper into more parts of the sky, and pluck out more galaxies.

Last May, the spacecraft's far-ultraviolet detector experienced an over-current condition, or essentially "shorted out," via a process called electron field emission. This detector sees higher-energy ultraviolet light, and thus hotter and younger stars within galaxies, than the telescope's other, near-ultraviolet detector. (The far-ultraviolet detector sees light with wavelengths between 135 and 180 nanometers, while the near-ultraviolet detector sees wavelengths between 180 and 280 nanometers.)

The far-ultraviolet detector has contributed significantly to the Galaxy Evolution Explorer's quest to understand how galaxies, including those like our own spiral Milky Way galaxy, blossom into maturity. It specializes in studies of star formation in nearby and distant galaxies. Perhaps the most significant discovery in this area is the identification of a transitional phase of galaxies, the teenagers of the galactic world. Astronomers long knew of young galaxies churning out stars, in addition to older, or dead, galaxies. But they did not know for certain whether the young ones mature into the older ones until the Galaxy Evolution Explorer found the missing links - the transitional galaxies (see http://www.jpl.nasa.gov/news/features.cfm?feature=1524).

In addition, one of the far-ultraviolet detector's most stunning finds is the humungous comet-like tail behind a speeding star called Mira. (See picture and article at http://www.jpl.nasa.gov/news/news.cfm?release=2007-090).

While the discovery of Mira's tail required the now-offline detector, almost all of the mission's targets could be seen by both detectors. Astronomers used the detectors' observations at different wavelengths to get an idea of a star or galaxy's temperature, age and mass. Much of this research can now be done by comparing near-ultraviolet data from the Galaxy Evolution Explorer with catalogued visible-light data from other telescopes. In addition, the wealth of far-ultraviolet observations to date will continue to be mined for decades to come.

The California Institute of Technology in Pasadena leads the Galaxy Evolution Explorer mission and is responsible for science operations and data analysis. JPL manages the mission and assembled the science instrument. The mission was developed under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. Researchers sponsored by Yonsei University in South Korea and the Centre National d'Etudes Spatiales (CNES) in France collaborated on this mission. Caltech manages JPL for NASA. ?

Graphics and additional information about the Galaxy Evolution Explorer are online at http://www.nasa.gov/galex and http://www.galex.caltech.edu.

Baby stars in the Rosette cloud

2010-04-12T11:33:00.001-04:00

Infrared image of the Rosette molecular cloud. Herschel collects the infrared light given out by dust and this image is a three-colour composite made of wavelengths at 70 microns (blue), 160 microns (green) and 250 microns (red). It was made with observations from Herschel’s Photoconductor Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE). The bright smudges are dusty cocoons containing massive protostars. The small spots near the centre of the image are lower mass protostars.

Credits: ESA/PACS & SPIRE Consortium/HOBYS Key Programme Consortia

Herschel’s latest image reveals the formation of previously unseen large stars, each one up to ten times the mass of our Sun. These are the stars that will influence where and how the next generation of stars are formed. The image is a new release of ‘OSHI’, ESA’s Online Showcase of Herschel Images.

The Rosette Nebula resides some 5,000 light years from Earth and is associated with a larger cloud that contains enough dust and gas to make the equivalent of 10,000 Sun-like stars. The Herschel image shows half of the nebula and most of the Rosette cloud. The massive stars powering the nebula lie to the right of the image but are invisible at these wavelengths. Each colour represents a different temperature of dust, from –263ºC (only 10ºC above absolute zero) in the red emission to –233ºC in the blue.

The bright smudges are dusty cocoons hiding massive protostars. These will eventually become stars containing around ten times the mass of the Sun. The small spots near the centre and in the redder regions of the image are lower mass protostars, similar in mass to the Sun.

ESA’s Herschel space observatory collects the infrared light given out by dust. This image is a combination of three infrared wavelengths, colour-coded blue, green and red in the image, though in reality the wavelengths are invisible to our eyes. It was created using observations from Herschel’s Photoconductor Array Camera and Spectrometer (PACS) and the Spectral and Photometric Imaging Receiver (SPIRE).

Herschel is showing astronomers such young, massive protostars for the first time, as part of the ‘Herschel imaging survey of OB Young Stellar objects’. Known as HOBYS, the survey targets young OB class stars, which will become the hottest and brightest stars.

“High-mass star-forming regions are rare and further away than low-mass ones,” says Frédérique Motte, Laboratoire AIM Paris-Saclay, France. So astronomers have had to wait for a space telescope like Herschel to reveal them.

It is important to understand the formation of high-mass stars in our Galaxy because they feed so much light and other forms of energy into their parent cloud they can often trigger the formation of the next generation of stars.

When astronomers look at distant galaxies, the star-forming regions they see are the bright, massive ones. Thus, if they want to compare our Galaxy to distant ones they must first understand high-mass star-formation here.

“Herschel will look at many other high-mass star-forming regions, some of them building stars up to a hundred times the mass of the Sun,” says Dr Motte, who plans to present the first scientific results from HOBYS at ESA’s annual ESLAB symposium to be held in the Netherlands, 4–7 May.

Source: ESA

13 astronauts celebrate 2 big space anniversaries

2010-04-12T10:28:00.001-04:00

The nose and forward cabin of the Space Shuttle Discovery is featured in this image photographed by a spacewalker during the mission's second spacewalk, in this image from NASA taken April 11, 2010.

CAPE CANAVERAL, Fla. – The astronauts aboard the orbiting shuttle-station complex celebrated two big anniversaries Monday as they geared up for the third and final spacewalk of their mission.

And the world was treated to the first recital of traditional Japanese music and poetry in space.

Monday marked the 49th anniversary of the first human spaceflight — by Soviet cosmonaut Yuri Gagarin on April 12, 1961 — and the 29th anniversary of the first shuttle launch.

In honor of Russia's Cosmonauts Day, Russian President Dmitry Medvedev called the residents of the International Space Station to wish them well. Three are Russian, two are American and one is Japanese.

"Space is something that unites all of us. It's a global issue," Medvedev told them.

He added: "Space is our highest priority, regardless of how hard the economic situation was in the country and will be, I'm sure."

Later in the morning, the two Japanese on board — the space station'sSoichi Noguchi and visiting shuttle astronaut Naoko Yamazaki — took a call from Japanese dignitaries and schoolchildren in Tokyo.

This is the first time two Japanese astronauts have flown together in space.

Yamazaki shared a haiku — or Japanese poem — she wrote after seeing Earth for the first time from space. Then, with Noguchi accompanying her on an electric keyboard, she performed a Japanese folk music springtime piece, "Sakura Sakura," which translates as "Cherry Blossom." Noguchi opened the piece with a few notes on a traditional wooden flute.

"This is probably the first time that you are going to hear the historic performance from space," Noguchi said.

The recital took place in Japan's big science lab, Kibo, or Hope.

Yamazaki will depart the space station Saturday, along with her six U.S. shuttle colleagues.

One more spacewalk still needs to be conducted to finish installing a new ammonia tank, on Tuesday. The astronauts will place a big cargo carrier back aboard Discovery on Thursday, after it's stuffed with old equipment and trash. Then on Friday, the shuttle will be inspected for any signs of micrometeorite damage.

This survey of the shuttle wings and nose usually is conducted after undocking. But Discovery's main antenna is broken, and there would be no way to transmit all the laser 3-D images to Mission Control for analysis.NASA added a day to the shuttle's visit so the inspection could be carried out at the station and the data could be sent using station resources.

Shuttle inspections became mandatory in space following the 2003 Columbia disaster.

Columbia lifted off on the first shuttle flight on April 12, 1981.

Source:- http://www.nasa.gov/mission_pages/shuttle/main/index.html

New Method of Classifying Planets Proposed

2010-04-12T10:20:00.000-04:00

Image comment: Artist's drawing depicting the dwarf planet Haumea, with its tow moons. The body has a prolonged shape that puzzles astronomers

Image credits: A. Feild (Space Telescope Science Institute)

The way the International Astronomical Union (IAU) goes about defining planets is a topic that many are uncomfortable with. A large proportion of all astronomers in the organization do not agree with the definitions by which the IAU decided which space object is classified as a planet, and which as a dwarf planet. This was made very obvious in 2006, when the organization voted – with only a few members in attendance – that Pluto was a dwarf planet, and not a real, full-size one. Now, experts propose a new method of defining what planets are, Technology Review reports.

The international scientific community has been trying to determine the best possible way of defining a planet for many ears, but most propositions on how to do that have thus far fallen short of their original goal. For instance, experts cannot classify an object on a planet based only on size, as throughout the Universe, size varies widely among planets. The IAU currently employs three criteria. The first is that the body needs to be orbiting the Sun, the second is that it must have sufficient mass to have formed a nearly spherical shape, and the third is that it needs to have cleared its orbit.

Pluto was deemed to be meeting the first two criteria, but not the third, because it passes through the orbit of Neptune. But critics say that, if Pluto was not deemed a planet because of this, then neither should Neptune be considered a planet, as it also failed the third criteria. Australian National University in Canberra expert Charles Lineweaver and Marc Norman decided to investigate the matter on their own, and the team now proposes a new approach to defining what a planet is. They basically suggest that any body which is not potato-shaped, and which has a diameter of more than 200 kilometers, can be considered a dwarf planet.

The problem with their approach is the fact that this definition raises the number of dwarf planets in the solar system considerably, while at the same time making the asteroid Vesta – a potato-shaped space rock much larger than 200 kilometers – a cosmic oddity. This method of defining space objects again puts Pluto as the number one dwarf planet, but it's unlikely to sit well with those who want to see the body established to its former “glory”. The main issue here remains elevating interest in this type of research, as more often than not, this translates into increased funding for this type of studies.

Source;- http://www.technologyreview.com/blog/arxiv/25034/

Analyzing the Sun's 'Magnetic Flux Ropes'

2010-04-12T07:07:00.000-04:00

Image comment: The three images reveal gases trapped in the flux rope at different temperatures, from 1.5 million degrees Celsius in the image on the left through to 2.5 million degrees Celsius in the right hand image
Image credits: JAXA / ISAS / NASA / STFC

Coronal mass ejections (CME) are some of the most interesting and important phenomena going on on the surface of our Sun. As the years pass, astronomers and astrophysicists gain a deeper and deeper understanding of how these structures form and develop. This is of tremendous importance, as the CME have the potential to create secondary events that can fry power grids and satellites, radiate our planet, and jeopardize the lives of people working aboard the International Space Station (ISS). It would now appear that one of the keys to learning more of CME is analyzing magnetic flux ropes.

As some experts put it, almost nothing happens on the Sun without the presence of very strong magnetic fields. These structures can take on various shapes and sizes, and they can trigger solar tsunamis, sunspots, coronal mass emissions and so on. Given the perilous nature of some of these events, it stands to reason that experts want to learn more about how they form. That is why scientists at the University College London (UCL), in the United Kingdom, used the Hinode satellite to gain more data on how these extremely large magnetic fields form.

Magnetic flux ropes are a type of field that can be readily detected in the interplanetary space as CME approach our planet. This led experts to assume that they play an important role in stimulating the emissions. “Magnetic flux ropes have been observed in interplanetary space for many years now and they are widely invoked in theoretical descriptions of how CME are produced. We now need observations to confirm or reject the existence of flux ropes in the solar atmosphere before an eruption takes place to see whether our theories are correct,” explains UCL expert Dr Lucie Green, the lead researcher on the investigation.

“Flux ropes are thought to play a vital role in the evolution of the magnetic field of the Sun. However, the physics of flux ropes is applied across the Universe. For example, a solar physics model of flux rope ejection was recently used to explain the jets driven by the accretion disks around the supermassive black holes found in the center of galaxies,” the scientist adds. Details of the work conducted at UCL were presented today, April 12, at the RAS National Astronomy Meeting, in Glasgow, Scotland, AlphaGalileo reports.