 WASHINGTON -- NASA is lending the Galaxy Evolution Explorer (GALEX) to the California Institute of Technology (Caltech) in Pasadena, where the spacecraft will continue its exploration of the cosmos. In a first-of-a-kind move for NASA, a Space Act Agreement was signed May 14 so the university soon can resume spacecraft operations and data management for the mission using private funds. "NASA sees this as an opportunity to allow the public to continue reaping the benefits from this space asset that NASA developed using federal funding," said Paul Hertz, NASA's Astrophysics Division director at the agency's headquarters in Washington. "This is an excellent example of a public/private partnership that will help further astronomy in the United States." The Galaxy Evolution Explorer spent about nine years as a NASA mission, probing the sky with its sharp ultraviolet eyes and cataloguing hundreds of millions of galaxies spanning 10 billion years of cosmic time. "This mission was full of surprises, and now more surprises are sure to come," said Chris Martin, who will remain the mission's principal investigator at Caltech. "It already has scanned a large fraction of the sky, improving our understanding of how galaxies grow and evolve. The astronomy community will continue those studies, in addition to spending more time on stars closer to home in our own galaxy." The spacecraft was placed in standby mode on Feb. 7 of this year. Soon, Caltech will begin to manage and operate the satellite, working with several international research groups to continue ultraviolet studies of the universe. Projects include cataloguing more galaxies across the entire sky; watching how stars and galaxies change over time; and making deep observations of the stars being surveyed for orbiting planets by NASA's Kepler mission. Data will continue to be made available to the public. "We're thrilled that the mission will continue on its path of discovery," said Kerry Erickson, the mission's project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "The Galaxy Evolution Explorer is like the 'little engine that could,' forging ahead into unexplored territory." During its time at NASA, the Galaxy Evolution Explorer made many discoveries involving various types of objects that light up our sky with ultraviolet light. Perhaps the most surprising of these was the discovery of a gargantuan comet-like tail behind a speeding star called Mira. Other finds included catching black holes "red-handed" as they munch away on stars, spying giant rings of new stars around old, presumed dead galaxies, and independently confirming the nature of dark energy. For astronomers, the most profound shift in their understanding of galaxy evolution came from the mission's findings about a "missing link" population of galaxies. These missing members helped explain how the two major types of galaxies in our universe -- the "red and dead" ellipticals and the blue spirals -- transition from one type to another. "We were able to trace the life of a galaxy," Martin said. "With the Galaxy Evolution Explorer's ultraviolet detectors, we were able to isolate the small amounts of star formation that are the signatures of galaxies undergoing an evolutionary change. We found that galaxies don't have a single personality, but may change types many times over their lifetime." The mission also captured a dazzling collection of snapshots, showing everything from ghostly nebulas to a spiral galaxy with huge, spidery arms. A slideshow showing some of the top images can be seen here: http://www.nasa.gov/mission_pages/galex/gallery-index.html . Under the new agreement, NASA maintains ownership and liability for the Galaxy Evolution Explorer spacecraft. When Caltech completes science activities, it will decommission the spacecraft for NASA. The mission's batteries and solar panels have an expected lifetime of 12 years or more, and the spacecraft will remain in orbit for at least 66 years, after which it will burn-up upon re-entry into Earth's atmosphere. The agreement can be renegotiated when it expires in three years. Orbital Sciences Corporation in Dulles, Va., which built the spacecraft, will continue performing flight control functions for Caltech associated with monitoring and commanding GALEX and participating in mission planning. Universal Space Network will continue providing the ground stations for communicating with the spacecraft.
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This image of the Cartwheel galaxy shows a rainbow of multi-wavelength observations from NASA missions, including the Galaxy Evolution Explorer (blue), the Hubble Space Telescope (green), the Spitzer Space Telescope (red) and the Chandra X-ray Observatory (purple).
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|  A NASA flight test designed to demonstrate the feasibility of inflatable spacecraft technology is coming down to the wire. The Inflatable Reentry Vehicle Experiment (IRVE-3) is the third in a series of suborbital flight tests of this new technology. It is scheduled to launch from the Wallops Flight Facility on Virginia's Eastern Shore this summer.
Technicians will vacuum pack the uninflated 10-foot (3.05 meters) diameter cone of high-tech inner tubes into a 22-inch (56 centimeters) diameter sounding rocket. During the flight test an on board system will inflate the tubes -- stretching a thermal blanket that covers them -to create an aeroshell or heat shield. That heat shield will protect a payload that consists of four segments including the inflation system, steering mechanisms, telemetry equipment and camera gear.
After launch the rocket will climb 287 miles (462 kilometers) into the skies over the Atlantic Ocean. The IRVE-3 will separate from the sounding rocket, its aeroshell will get pumped full of nitrogen and then the inflated heat shield and payload will plummet back through Earth's atmosphere. Cameras and instruments will transmit pictures and data to researchers in the Wallops control room the entire time. Engineers at NASA's Langley Research Center in Hampton, Va., who are overseeing the project, have spent the last three years preparing for the test. They have studied designs, assessed materials in laboratories and wind tunnels and subjected hardware to thermal and pressure loads beyond what it should face in flight.
"We have to do all kinds of different testing," said flight systems engineer Carrie Rhoades. "We do high temperature tunnel tests in a number of facilities to check out all different types of thermal protection system materials. For IRVE-3 we know what should work, but for future missions we want to go bigger to carry larger payloads, so we've got to keep testing and trying out different materials."
One of the last hurdles before launch was a complete shakedown of the system in NASA Langley's Transonic Dynamics Tunnel, which technicians de-pressurized to mimic upper atmospheric conditions where the aeroshell will be deployed. The team collected data in the control room as they watched the simulated 20-minute flight of IRVE-3. Since a wind tunnel test couldn't replicate the actual flight and separation of the spacecraft from the sounding rocket, the real action began seven minutes and 11 seconds after the test started. That's when cutters -- designed to snip the strings on the bag that contained the packed heat shield -- were supposed to start. For a brief moment the team held its collective breath when the cutters seem to pause, but then came the sigh of relief as the strings continued to pop open. The inflatable rings and their thermal blanket started unfurling as the inflation system pumped nitrogen in correct sequence.
"There are an awful lot of complex systems packed inside the payload on IRVE-3," said Robert Dillman, the chief engineer for IRVE-3. "When it works it looks simple and that's a good thing. But there are a lot of internal parts that have to work together in order to make that simple function achievable."
The inflation system test went off without a hitch so the Inflatable Reentry Vehicle Experiment can go to Wallops to be readied for launch.
IRVE-3 is one of NASA's many research efforts to develop new technologies to advance space travel. It's part of a project called HIAD for Hypersonic Inflatable Aerodynamic Decelerator -- within NASA's Office of the Chief Technologist's Game Changing Development (GCD) Program.
"A HIAD could give NASA more options for future planetary missions or to return cargo to Earth," said Neil Cheatwood, GCD principal investigator for HIAD. "When we go to other planets with an atmosphere, we actually use that atmosphere to slow us down with an aeroshell or an aerodynamic decelerator. But the size of that aeroshell is currently limited. We can't go bigger than the diameter of the launch vehicle."
An inflatable heat shield could accommodate larger payloads that could deliver more and heavier science instruments and tools for exploration -- changing the way we explore other worlds.
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Engineers checked out the Inflatable Reentry Vehicle Experiment after the successful completion of an inflation system test. The IRVE-3 is scheduled to launch on a sounding rocket later this summer.
Credit: NASA/ Sean Smith
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|  PASADENA, Calif. -- Observations from NASA's Wide-field Infrared Survey Explorer (WISE) have led to the best assessment yet of our solar system's population of potentially hazardous asteroids. The results reveal new information about their total numbers, origins and the possible dangers they may pose. Potentially hazardous asteroids, or PHAs, are a subset of the larger group of near-Earth asteroids. The PHAs have the closest orbits to Earth's, coming within five million miles (about eight million kilometers), and they are big enough to survive passing through Earth's atmosphere and cause damage on a regional, or greater, scale. The new results come from the asteroid-hunting portion of the WISE mission, called NEOWISE. The project sampled 107 PHAs to make predictions about the entire population as a whole. Findings indicate there are roughly 4,700 PHAs, plus or minus 1,500, with diameters larger than 330 feet (about 100 meters). So far, an estimated 20 to 30 percent of these objects have been found. While previous estimates of PHAs predicted similar numbers, they were rough approximations. NEOWISE has generated a more credible estimate of the objects' total numbers and sizes. "The NEOWISE analysis shows us we've made a good start at finding those objects that truly represent an impact hazard to Earth," said Lindley Johnson, program executive for the Near-Earth Object Observation Program at NASA Headquarters in Washington. "But we've many more to find, and it will take a concerted effort during the next couple of decades to find all of them that could do serious damage or be a mission destination in the future." The new analysis also suggests that about twice as many PHAs as previously thought are likely to reside in "lower-inclination" orbits, which are more aligned with the plane of Earth's orbit. In addition, these lower-inclination objects appear to be somewhat brighter and smaller than the other near-Earth asteroids that spend more time far away from Earth. A possible explanation is that many of the PHAs may have originated from a collision between two asteroids in the main belt lying between Mars and Jupiter. A larger body with a low-inclination orbit may have broken up in the main belt, causing some of the fragments to drift into orbits closer to Earth and eventually become PHAs. Asteroids with lower-inclination orbits would be more likely to encounter Earth and would be easier to reach. The results therefore suggest more near-Earth objects might be available for future robotic or human missions. "NASA's NEOWISE project, which wasn't originally planned as part of WISE, has turned out to be a huge bonus," said Amy Mainzer, NEOWISE principal investigator, at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Everything we can learn about these objects helps us understand their origins and fate. Our team was surprised to find the overabundance of low-inclination PHAs. Because they will tend to make more close approaches to Earth, these targets can provide the best opportunities for the next generation of human and robotic exploration." The discovery that many PHAs tend to be bright says something about their composition; they are more likely to be either stony, like granite, or metallic. This type of information is important in assessing the space rocks' potential hazards to Earth. The composition of the bodies would affect how quickly they might burn up in our atmosphere if an encounter were to take place. The NEOWISE results have been accepted for publication in the Astrophysical Journal. The WISE spacecraft scanned the sky twice in infrared light before entering hibernation mode in early 2011. It catalogued hundreds of millions of objects, including super-luminous galaxies, stellar nurseries and closer-to-home asteroids. The NEOWISE project snapped images of about 600 near-Earth asteroids, about 135 of which were new discoveries. Because the telescope detected the infrared light, or heat, of asteroids, it was able to pick up both light and dark objects, resulting in a more representative look at the entire population. The infrared data allowed astronomers to make good measurements of the asteroids' diameters and, when combined with visible light observations, how much sunlight they reflect.
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| This diagram illustrates the differences between orbits of a typical near-Earth asteroid (blue) and a potentially hazardous asteroid, or PHA (orange). Image credit: NASA/JPL-Caltech |
JPL manages, and operates the Wide-field Infrared Survey Explorer for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing and archiving take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. |  GREENBELT, Md - Observations with NASA's Chandra X-ray Observatory have provided the first X-ray evidence of a supernova shock wave breaking through a cocoon of gas surrounding the star that exploded. This discovery may help astronomers understand why some supernovas are much more powerful than others.
On Nov. 3, 2010, a supernova was discovered in the galaxy UGC 5189A, located about 160 million light years away. Using data from the All Sky Automated Survey telescope in Hawaii taken earlier, astronomers determined this supernova exploded in early October 2010 (in Earth's time-frame).
This composite image of UGC 5189A shows X-ray data from Chandra in purple and optical data from Hubble Space Telescope in red, green and blue. SN 2010jl is the very bright X-ray source near the top of the galaxy.
A team of researchers used Chandra to observe this supernova in December 2010 and again in October 2011. The supernova was one of the most luminous that has ever been detected in X-rays.
In optical light, SN 2010jl was about ten times more luminous than a typical supernova resulting from the collapse of a massive star, adding to the class of very luminous supernovas that have been discovered recently with optical surveys. Different explanations have been proposed to explain these energetic supernovas including (1) the interaction of the supernova's blast wave with a dense shell of matter around the pre-supernova star, (2) radioactivity resulting from a pair-instability supernova (triggered by the conversion of gamma rays into particle and anti-particle pairs), and (3) emission powered by a neutron star with an unusually powerful magnetic field.
In the first Chandra observation of SN 2010jl, the X-rays from the explosion's blast wave were strongly absorbed by a cocoon of dense gas around the supernova. This cocoon was formed by gas blown away from the massive star before it exploded.
In the second observation taken almost a year later, there is much less absorption of X-ray emission, indicating that the blast wave from the explosion has broken out of the surrounding cocoon. The Chandra data show that the gas emitting the X-rays has a very high temperature -- greater than 100 million degrees Kelvin – strong evidence that it has been heated by the supernova blast wave.
The energy distribution, or spectrum, of SN 2010jl in optical light reveals features that the researchers think are explained by the following scenario: matter around the supernova has been heated and ionized (electrons stripped from atoms) by X-rays generated when the blast wave plows through this material. While this type of interaction has been proposed before, the new observations directly show, for the first time, that this is happening.
This discovery therefore supports the idea that some of the unusually luminous supernovas are caused by the blast wave from their explosion ramming into the material around it.
In a rare example of a cosmic coincidence, analysis of the X-rays from the supernova shows that there is a second unrelated source at almost the same location as the supernova. These two sources strongly overlap one another as seen on the sky. This second source is likely to be an ultraluminous X-ray source, possibly containing an unusually heavy stellar-mass black hole, or an intermediate mass black hole.
These results were published in a paper appearing in the May 1st, 2012 issue of The Astrophysical Journal Letters. The authors were Poonam Chandra (Royal Military College of Canada, Kingston, Canada), Roger Chevalier and Christopher Irwin (University of Virginia, Charlottsville, VA), Nikolai Chugai (Institute of Astronomy of Russian Academy of Sciences, Moscow, Russia), Claes Fransson (Stockholm University, Sweden), and Alicia Soderberg (Harvard-Smithsonian Center for Astrophysics, Cambridge, MA).
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| Chandra image of UGC 5189A showing the supernova shockwave Photo Credit: NASA |
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GREENBELT, Md - This mottled landscape showing the impact crater Tycho is among the most violent-looking places on our moon. Astronomers didn't aim NASA's Hubble Space Telescope to study Tycho, however. The image was taken in preparation to observe the transit of Venus across the sun's face on June 5-6.
Hubble cannot look at the sun directly, so astronomers are planning to point the telescope at the Earth's moon, using it as a mirror to capture reflected sunlight and isolate the small fraction of the light that passes through Venus's atmosphere. Imprinted on that small amount of light are the fingerprints of the planet’s atmospheric makeup.
These observations will mimic a technique that is already being used to sample the atmospheres of giant planets outside our solar system passing in front of their stars. In the case of the Venus transit observations, astronomers already know the chemical makeup of Venus's atmosphere, and that it does not show signs of life on the planet. But the Venus transit will be used to test whether this technique will have a chance of detecting the very faint fingerprints of an Earth-like planet, even one that might be habitable for life, outside our solar system that similarly transits its own star. , Venus is an excellent proxy because it is similar in size and mass to our planet.
The astronomers will use an arsenal of Hubble instruments, the Advanced Camera for Surveys, Wide Field Camera 3, and Space Telescope Imaging Spectrograph, to view the transit in a range of wavelengths, from ultraviolet to near-infrared light. During the transit, Hubble will snap images and perform spectroscopy, dividing the sunlight into its constituent colors, which could yield information about the makeup of Venus's atmosphere.
Hubble will observe the moon for seven hours, before, during, and after the transit so the astronomers can compare the data. Astronomers need the long observation because they are looking for extremely faint spectral signatures. Only 1/100,000th of the sunlight will filter through Venus's atmosphere and be reflected off the moon.
This image, taken with Hubble's Advanced Camera for Surveys, reveals lunar features as small as roughly 560 feet (170 meters) across. The large "bulls-eye" near the top of the picture is the impact crater, caused by an asteroid strike about 100 million years ago. The bright trails radiating from the crater were formed by material ejected from the impact area during the asteroid collision. Tycho is about 50 miles (80 kilometers) wide and is circled by a rim of material rising almost 3 miles (5 kilometers) above the crater floor. The image measures 430 miles (700 kilometers) across, which is slightly larger than New Mexico.
Because the astronomers only have one shot at observing the transit, they had to carefully plan how the study would be carried out. Part of their planning included the test observations of the moon, made on Jan. 11, 2012, as shown in the release image.
Hubble will need to be locked onto the same location on the moon for more than seven hours, the transit's duration. For roughly 40 minutes of each 96-minute orbit of Hubble around the Earth, the Earth occults Hubble's view of the moon. So, during the test observations, the astronomers wanted to make sure they could point Hubble to precisely the same target area.
This is the last time this century sky watchers can view Venus passing in front of the sun. The next transit won't happen until 2117. Venus transits occur in pairs, separated by eight years. The last event was witnessed in 2004.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.
|  GREENBELT, Md - For the last few decades, space scientists have generally accepted that the bubble of gas and magnetic fields generated by the sun – known as the heliosphere – moves through space, creating three distinct boundary layers that culminate in an outermost bow shock. This shock is similar to the sonic boom created ahead of a supersonic jet. Earth itself certainly has one of these bow shocks on the sunward side of its magnetic environment, as do most other planets and many stars. A collection of new data from NASA's Interstellar Boundary Explorer (IBEX), however, now indicate that the sun does not have a bow shock.
In a paper appearing online in Science Express on May 10, 2012, scientists compile data from IBEX, NASA's twin Voyager spacecraft, and computer models to show that the heliosphere just isn't moving fast enough to create a bow shock in the tenuous and highly magnetized region in our local part of the galaxy.
"IBEX gives a global view. It shows the whole of this region," says Eric Christian who is the mission scientist for IBEX at NASA's Goddard Space Flight Center in Greenbelt, Md. and who was formerly the program scientist for Voyager. "At the same time the Voyager spacecraft are actually there, in situ, measuring its environment at two locations. The combination of IBEX and Voyager gives you great science and now the new IBEX results strongly indicate that there is no bow shock."
Since the 1980s, the boundaries of the heliosphere have largely been assumed to be a series of three. The first is a fairly spherical boundary called the termination shock -- the point where the solar wind streaming from the sun slows down below supersonic speeds. From there the wind continues more slowly until it collides with the material in the rest of the galaxy and is pushed back, deflecting around the outskirts of the heliosphere, streaming back toward the tail of the moving bubble. This second boundary is called the heliopause. The third boundary was thought to be the bow shock, formed as the heliosphere plowed its way through the local galactic cloud the same way a supersonic jet pushes aside the air as it moves.
The two Voyager spacecraft have confirmed the existence of the first boundary, and have seen evidence for the second as they move toward it. However, each Voyager spacecraft has seen different things on their respective trips – one moving in a more northerly direction, one moving more to the south. They've encountered different regions at different distances from the sun, suggesting the very shape of the heliosphere is squashed and asymmetrical. Scientists believe this asymmetry is caused by the force and direction of magnetic fields ramming into the heliosphere from outside, the same way a hand pushing on a balloon will force it out of shape. This was the first clue that there's a strong magnetic field exerting pressure on the outskirts of the solar system. Independently, IBEX has seen a well-defined band, or ribbon, at the edge of the heliosphere, believed to be defined by this external magnetic field. Other studies from IBEX have helped quantify the magnitude of the magnetic field, showing that it is on the strong end of what was previously thought possible.
"We've seen one after another signature of a very strong magnetic field in the galactic environment," says Nathan Schwadron, a space scientist at the University of New Hampshire in Durham who is one of the authors on the paper. "That magnetic field influences the structure of the heliosphere and the boundaries themselves. That leads to a whole new paradigm."
Along with increased evidence for a strong external magnetic field, IBEX has also provided a new measurement for the speed of the heliosphere itself with respect to the local cloud.
"We recently analyzed two years worth of IBEX data, and they showed that the speed of the heliosphere – with respect to the local cloud of material – is only 52,000 miles per hour, instead of the previously believed 59,000," says David McComas at the Southwest Research Institute in San Antonio, Texas, who is first author on this paper and also the principal investigator for IBEX. "That might not seem like a huge difference, but it translates to a quarter less pressure exerted on the boundaries of the heliosphere. This means there's a very different interaction, a much weaker interaction, than previously thought."
In essence, it means that, like an airplane going too slowly to produce a sonic boom, the heliosphere isn't moving fast enough to create a bow shock, given the density and pressures of the material its moving through.
The heliosphere's boundaries lie roughly 10 billion miles away from Earth, but are nonetheless crucial for understanding our place in the universe. Indeed, the heliopause provides some protection for our solar system from the harsh, radiation environment surrounding it. By knowing the nature of these boundaries, scientists can start to better understand the propagation of particles that do have enough energy and speed to make it into our environment.
As scientists incorporate this substantive new understanding into their physical models, they will also be waiting for more evidence from both IBEX and the Voyagers, which they hope will continue to send back observations for many years to come.
"Imagine the point at which Voyager crosses the threshold of the heliopause and either does or does not see what IBEX is predicting," says Schwadron. "There will be enormous opportunities for scientific advancement."
|  PASADENA, Calif. -- With its daily supply of solar energy increasing, NASA's durable Mars Exploration Rover Opportunity has driven off the sunward-tilted outcrop, called Greeley Haven, where it worked during its fifth Martian winter. (EDITORS NOTE: each year on Mars is about two Earth years long) Opportunity's first drive since Dec. 26, 2011, took the rover about 12 feet (3.67 meters) northwest and downhill on Tuesday, May 8. The rover operations team at NASA's Jet Propulsion Laboratory, Pasadena, Calif., received confirmation of the completed drive late Tuesday, relayed from NASA's Mars Odyssey orbiter. "We're off the Greeley Haven outcrop onto the sand just below it," said rover driver Ashley Stroupe of JPL. "It feels good to be on the move again." While at Greeley Haven for the past 19 weeks, Opportunity used the spectrometers and microscopic imager on its robotic arm to inspect more than a dozen targets within reach on the outcrop. Radio Doppler signals from the stationary rover during the winter months served an investigation of the interior of Mars by providing precise information about the planet's rotation. Opportunity will look back with its panoramic camera to acquire multi-filter imaging of the surface targets it studied on Greeley Haven. The rover team will also check that the power supply still looks sufficient with the rover at a reduced tilt. Opportunity kept a northward tilt of about 15 degrees in recent months at its winter haven. In Mars' southern hemisphere, that tilt kept its solar panels favorably angled toward the winter sun low in the northern sky. The winter solstice for southern Mars was at the end of March. The northward tilt after Tuesday's drive is about 8 degrees. Opportunity has been exploring the Meridiani region of Mars since landing in January 2004. It arrived at the Cape York section of the rim of Endeavour Crater in August 2011, and has been studying rock and soil targets on Cape York since then. "Our next goal is a few meters farther north on Cape York, at a bright-looking patch of what may be dust," said Opportunity science-team member Matt Golombek of JPL. "We haven't been able to see much dust in Meridiani. This could be a chance to learn more about it." Beyond the dust patch, the team intends to use Opportunity to study veins in bedrock around the northern edge of Cape York. A vein inspected before winter contained gypsum deposited long ago by mineral-laden water flowing through a crack in the rock. Endeavour Crater offers Opportunity a setting for plenty of productive work. The crater is 14 miles (22 kilometers) in diameter -- more than 20 times wider than Victoria Crater, which Opportunity examined for two years. One type of deposit detected from orbit at some locations on Endeavour's rim contains ancient clay minerals, interpreted as evidence of ancient, wet conditions with less acidity than the ancient, wet environments recorded at sites Opportunity visited during its first seven years on Mars. Unless wind removes some dust from Opportunity's solar array, allowing more sunlight to reach the solar cells, the rover will need to work during the next few weeks at locations with no southward slope. "We'll head south as soon as power levels are adequate to handle the slopes where we'll go," said Mars Exploration Rover Deputy Project Scientist Diana Blaney of JPL. "There are some deposits on Cape York where, based on their geologic setting, we think there's a good chance of finding ancient clays." A later destination for Opportunity lies farther south, on a rim segment named Cape Tribulation, where ancient clays have been detected from orbit. Opportunity and its rover twin, Spirit, completed their three-month prime missions on Mars in April 2004. Both rovers continued for years of bonus, extended missions. Both have made important discoveries about wet environments on ancient Mars that may have been favorable for supporting microbial life. Spirit stopped communicating in 2010. NASA launched its next-generation Mars rover, Curiosity, on Nov. 26 for arrival at Mars' Gale Crater in August 2012. Landing successfully is quite a challenge, and Curiosity's mission is pioneering a new landing method to enable use of a heavier rover. Curiosity is about twice as long and more than five times as heavy as any previous Mars rover. Its size and mass accommodate a science payload designed to study whether the landing region has had environmental conditions favorable for supporting microbial life, including chemical ingredients for life.
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The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter recorded a scene on Jan. 29, 2012, that includes the first color image from orbit showing the three-petal lander of NASA's Mars Exploration Rover Spirit mission. Spirit drove off that lander platform in January 2004 and spent most of its six-year working life in a range of hills about two miles to the east. Photo Credit: NASA
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|  PARIS - Just weeks after celebrating its tenth year in orbit, communication with the Envisat satellite was suddenly lost on 8 April. Following rigorous attempts to re-establish contact and the investigation of failure scenarios, the end of the mission is being declared.
A team of engineers has spent the last month attempting to regain control of Envisat, investigating possible reasons for the problem. Despite continuous commands sent from a widespread network of ground stations, there has been no reaction yet from the satellite. As there were no signs of degradation before the loss of contact, the team has been collecting other information to help understand the satellite’s condition. These include images from ground radar and the French Pleiades satellite. With this information, the team has gradually elaborated possible failure scenarios. One is the loss of the power regulator, blocking telemetry and telecommands. Another scenario is a short circuit, triggering a ‘safe mode’ – a special mode ensuring Envisat’s survival. A second anomaly may have occurred during the transition to safe mode, leaving the satellite in an intermediate and unknown condition. Although chances of recovering Envisat are extremely low, the investigation team will continue attempts to re-establish contact while considering failure scenarios for the next two months. The outstanding performance of Envisat over the last decade led many to believe that it would be active for years to come, at least until the launch of the follow-on Sentinel missions.
However, Envisat had already operated for double its planned lifetime, making it well overdue for retirement. With ten sophisticated sensors, Envisat has observed and monitored Earth’s land, atmosphere, oceans and ice caps during its ten-year lifetime, delivering over a thousand terabytes of data. An estimated 2500 scientific publications so far have been based on this information, furthering our knowledge of the planet. During those ten years, Envisat witnessed the gradual shrinking of Arctic sea ice and the regular opening of the polar shipping routes during summer months. Together with other satellites, it monitored the global sea-level height and regional variations, as well as global sea-surface temperatures with a precision of a few tenths of a degree. Years of Envisat data have led to a better understanding of ocean currents and chlorophyll concentrations. In the atmosphere, the satellite observed air pollution increase in Asia and its stability in Europe and North America, and measured carbon dioxide and methane concentrations. Envisat also monitored the Antarctica ozone hole variations. Over land, it mapped the speed of ice streams in Antarctica and Greenland. Its images were used regularly to update the global maps of land use, including the effects of deforestation. Using its imaging radar, Envisat mapped ground displacements triggered by earthquakes and volcanic eruptions, improving understanding of tectonics and volcanic mechanisms. Envisat provided crucial Earth observation data not only to scientists, but also to many operational services, such as monitoring floods and oil spills. Its data were used for supporting civil protection authorities in managing natural and man-made disasters. Envisat has also contributed valuable information to the services within Europe’s Global Monitoring for Environmental Security (GMES) programme, paving the way for the next generation of satellites. Now with the end of the mission, the launch of the upcoming GMES Sentinel satellites has become even more urgent to ensure the continuity of data to users, improve the management of the environment, understand and mitigate the effects of climate change and ensure civil security.
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| Envysat as seen fron the french national security satellite Pleadese Photo Credit: ESA |
|  Sutter's Mill, Calif - Meteorite fragments were recently scattered around Sutter’s Mill in California, the same region where the first nugget of gold was found that sparked the Gold Rush in 1848. Scientists believe the meteorites may hold answers to unsolved mysteries about our solar system and the origins of molecules necessary for life. When the Gold Rush began, people headed to California seeking their fortune. Now, with this meteorite hunt, people once again have flocked to this area to search for scientific treasures.
What scientists call the Sutter's Mill Meteorite landed at 7:51 a.m. PDT on Sunday, April 22, 2012, outside of Lotus, Calif., in a horse pasture located in the Sierra Nevada Mountains. The de Haas family owns the property.
"It sounded like a sonic boom but longer,” said Alan Ehrgott, who lives in the Sutter Mill area. “It seemed to last 45 seconds. It stopped me in my tracks."
The de Haas family has generously donated the meteorite to NASA.
Merv de Hass, who owns the land where the meteorite was found, donated the fragment to NASA. "If I could contribute to science in some small way, then that would be great,” said de Haas. “I'm looking forward to the results."
Eugena de Haas lives on the land where the meteorite was found. She informed NASA scientists that they were approved to search that land. "I feel like I have done a service to my country," she said.
“The de Haas family has welcomed NASA’s involvement with open arms,” said NASA Lunar Science Institute (NLSI) Director Yvonne Pendleton. “I want to express my personal gratitude to them. They should be commended for their contribution to scientific discovery."
This is a very rare type of meteor and scientists have precious few samples of this kind of material. The meteorites are very interesting to scientists from an astrobiology perspective, as they contain molecules related to how the building blocks for life on Earth may have been delivered from outer space. Scientist believe that this meteor could hold the answers to the origin of life on Earth and the universe. By studying the meteor, scientists also will learn more about the early solar system and the formation of our planets.
“This is among the most chemically primitive meteorites,” said NLSI Deputy Director Greg Schmidt. "It’s like asking ‘how did life on Earth begin?’ and then having a fossil fall right in your back yard. This is exciting stuff — who knows what’s inside? The Sutter’s Mill Meteorite could be the most profound sample collected in over 40 years.”
People who work at NASA had an opportunity to participate in the meteor hunt. Peter Jenniskens, a meteor astronomer with the SETI Institute working in collaboration with NLSI, led the search. A group of NASA Ames employees went to the mountains to assist in the search on Thursday, May 3 and Friday, May 4, 2012.
"It’s heartwarming to see people coming together in the name of science,” said Pendelton.
For Jenniskens, finding this meteorite is equivalent to winning the lottery. Because this discovery is a very rare carbonaceous chrondrite that decomposes quickly in damp weather, the science team hopes to cover a large amount of terrain to identify possible candidate pieces for recovery before they decompose.
As Jenniskens finds the meteorites, he notes their exact location to better understand the meteor’s fall to Earth.
"I am grateful this meteorite was found quickly,” Jenniskens said. “We need to recover as much material as possible from the damp environment before weather affects the rocks too badly."
Since there was such a large piece of land to search in a short amount of time, Airship Ventures' Zeppelin was called in to help conduct the search. The airship provides an ideal search vehicle, due to its ability to fly slowly and methodically over an area with a group of trained observers aboard to relay possible candidate coordinates to a ground team for investigation. The airship also carries a high definition gyrostabilized camera, often used to help photograph sporting events. In addition to the camera mounted on the airship, observers in the ship used binoculars and cameras to help spot burn patches and potential impact sites.
"I suspect this is the first time in history that anyone has searched for meteorites with an airship," said Schmidt.
So far, the fragment donated by the de Haas family was one of the largest meteorites recovered, but the search for even bigger samples will continue over the next few months. The search for more fragments will continue for the next month. However, scientists will be studying these meteorite samples for many years to come.
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Fragments of the Sutter’s Mill meteorite fall collected by NASA Ames and SETI Institute meteor astronomer Dr. Peter Jenniskens in the evening of Tuesday April 24, two days after the fall. This was the second recovered find.
Image credit: NASA / Eric James
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|  PASADENA - Team members of NASA's Mars Science Laboratory mission took a test rover to Dumont Dunes in California's Mojave Desert this week to improve knowledge of the best way to operate a similar rover, Curiosity, currently flying to Mars for an August landing. The test rover that they put through paces on various sandy slopes has a full-scale version of Curiosity's mobility system, but it is otherwise stripped down so that it weighs about the same on Earth as Curiosity will weigh in the lesser gravity of Mars. Information collected in these tests on windward and downwind portions of dunes will be used by the rover team in making decisions about driving Curiosity on dunes near a mountain in the center of Gale Crater. First, however, the Mars Science Laboratory spacecraft, launched Nov. 26, 2011, must put Curiosity safely onto the ground. Safe landing on Mars is never assured, and this mission will use innovative methods to land the heaviest vehicle in the smallest target area ever attempted on Mars. Advances in landing heavier payloads more precisely are steps toward eventual human missions to Mars.
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Mars Science Laboratory mission team members ran mobility tests on California sand dunes in early May 2012 in preparation for operating the Curiosity rover, currently en route to Mars, after its landing in Mars' Gale Crater. This test rover, called Scarecrow because it doesn't have an onboard computer "brain" like Curiosity, has a full-scale version of Curiosity's mobility system, but it is otherwise stripped down so that it weighs about the same on Earth as Curiosity will weigh in the lesser gravity of Mars. Each wheel has a diameter of 20 inches (50 centimeters).
The tests for driving on sand dunes were conducted on the Dumont Dunes, near Death Valley in California. Information collected about Scarecrow's performance in driving up various slopes on windward and downwind portions of dunes will be used by the rover team in decisions about driving on dunes near Mount Sharp inside Gale Crater.
NASA's Mars Science Laboratory mission launched on Nov. 26, 2011, and will deliver the rover Curiosity to Gale Crater on Mars on Aug. 6, 2012, Universal Time and EDT (night of Aug. 5, PDT). With 10 science instruments, Curiosity will investigate whether the area has ever offered environmental conditions favorable for microbial life. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Mars Science Laboratory mission for NASA’s Science Mission Directorate, Washington, and built Curiosity.
Image credit: NASA/JPL-Caltech
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Curiosity is on track for landing the evening of Aug. 5, 2012, PDT (early on Aug. 6, Universal Time and EDT) to begin a two-year prime mission. Researchers plan to use Curiosity to study layers in Gale Crater's central mound, Mount Sharp. The mission will investigate whether the area has ever offered an environment favorable for microbial life. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for the NASA Science Mission Directorate, Washington. |
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