Saturn mission: Cassini instrument learns new tricks

Dec. 20, 2012 — For seven years, a mini-fridge-sized instrument aboard NASA's Cassini spacecraft reliably investigated weather patterns swirling around Saturn; the hydrocarbon composition of the surface of Saturn's moon Titan; the aerosol layers of Titan's haze; and dirt mixing with ice in Saturn's rings. But this year the instrument -- the visual and infrared mapping spectrometer (VIMS) -- has been testing out some new telescopic muscles.

This Friday, Dec. 21, the spectrometer will be tracking the path of Venus across the face of the sun from its perch in the Saturn system. Earthlings saw such a transit earlier this year, from June 5 to 6. But the observation in December will be the first time a spacecraft has tracked a transit of a planet in our solar system from beyond Earth orbit.

Cassini will collect data on the molecules in Venus's atmosphere as sunlight shines through it. But learning about Venus actually isn't the point of the observation. Scientists actually want to use the occasion to test the VIMS instrument's capacity for observing planets outside our solar system.

"Interest in infrared investigations of extrasolar planets has exploded in the years since Cassini launched, so we had no idea at the time that we'd ask VIMS to learn this new kind of trick," said Phil Nicholson, the VIMS team member based at Cornell University, Ithaca, N.Y., who is overseeing the transit observations. "But VIMS has worked so well at Saturn so far that we can start thinking about other things it can do."

VIMS will be able to complement exoplanet studies by space telescopes such as NASA's Hubble and Spitzer space telescopes. VIMS scientists are particularly interested in investigating atmospheric data -- such as signatures of methane -- from far-off star systems in near-infrared wavelengths.

The pointing has to be very accurate to get one of those extrasolar planets in VIMS's viewfinder, but the instrument has had lots of practice pointing at other stars. Earlier this year, VIMS obtained its first successful observation of a transit by the exoplanet HD 189733b. Scientists want to improve these observations by reducing the amount of noise in the signal.

In April, VIMS demonstrated another kind of flexibility by turning its eyes to the warm fissures slashing cross the surface of Saturn's moon Enceladus. VIMS is particularly good at taking thermal data in temperatures around minus 100 degrees Fahrenheit (200 kelvins). So while it is good at tracking hotspots and turbulent clouds on Saturn, VIMS is generally unable to detect thermal emission from Titan, the icy satellites or the rings, since their temperatures are much colder than that.

But the fissures on Enceladus, which scientists have called tiger stripes, are just hot enough for VIMS to detect heat coming from them.

"For the first time, we were able to see that the jets coming from the surface of Enceladus originated in very small, very hot spots," said Bonnie Buratti, a VIMS scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "This new observation is good evidence for liquid water underneath the surface."

VIMS is one of 12 instruments on Cassini, which launched in 1997 and began orbiting Saturn in 2004. "We built Cassini to be hardy, and we're pleased that the spacecraft has been weathering the extreme conditions of the Saturn system remarkably well," said Robert Mitchell, Cassini program manager at JPL. "It isn't too tired to try something new."

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, Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The visual and infrared mapping spectrometer team is based at the University of Arizona, Tucson.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by NASA/Jet Propulsion Laboratory.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Clays on Mars: More plentiful than expected

Dec. 20, 2012 — A new study co-authored by the Georgia Institute of Technology indicates that clay minerals, rocks that usually form when water is present for long periods of time, cover a larger portion of Mars than previously thought. In fact, Assistant Professor James Wray and the research team say clays were in some of the rocks studied by Opportunity when it landed at Eagle crater in 2004. The rover only detected acidic sulfates and has since driven about 22 miles to Endeavour Crater, an area of the planet Wray pinpointed for clays in 2009.

The study is published online in the current edition of Geophysical Research Letters.

The project, which was led by Eldar Noe Dobrea of the Planetary Science Institute, identified the clay minerals using a spectroscopic analysis from the Mars Reconnaissance Orbiter. The research shows that clays also exist in the Meridiani plains that Opportunity rolled over as it trekked toward its current position.

"It's not a surprise that Opportunity didn't find clays while exploring," said Wray, a faculty member in the School of Earth and Atmospheric Sciences. "We didn't know they existed on Mars until after the rover arrived. Opportunity doesn't have the same tools that have proven so effective for detecting clays from orbit."

The clay signatures near Eagle crater are very weak, especially compared to those along the rim and inside Endeavour crater. Wray believes clays could have been more plentiful in the past, but Mars' volcanic, acidic history has probably eliminated some of them.

"It was also surprising to find clays in geologically younger terrain than the sulfates," said Dobrea. Current theories of Martian geological history suggest that clays, a product of aqueous alteration, actually formed early on when the planet's waters were more alkaline. As the water acidified due to volcanism, the dominant alteration mineralogy became sulfates. "This forces us to rethink our current hypotheses of the history of water on Mars," he added.

Even though Opportunity has reached an area believed to contain rich clay deposits, the odds are still stacked against it. Opportunity was supposed to survive for only three months. It's still going strong nine years later, but the rover's two mineralogical instruments don't work anymore. Instead, Opportunity must take pictures of rocks with its panoramic camera and analyze targets with a spectrometer to try and determine the composition of rock layers.

"So far, we've only been able to identify areas of clay deposits from orbit," said Wray. "If Opportunity can find a sample and give us a closer look, we should be able to determine how the rock was formed, such as in a deep lake, shallow pond or volcanic system."

As for the other rover on the other side of Mars, Curiosity's instruments are better equipped to search for signs of past or current conditions for habitable life, thanks in part to Opportunity. Wray is a member of Curiosity's science team.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by Georgia Institute of Technology.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

E. Z. Noe Dobrea, J. J. Wray, F. J. Calef, T. J. Parker, S. L. Murchie. Hydrated minerals on Endeavour Crater's rim and interior, and surrounding plains: New insights from CRISM data. Geophysical Research Letters, 2012; 39 (23) DOI: 10.1029/2012GL053180

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Meteorite triggered scientific 'Gold Rush'

Dec. 20, 2012 — A meteorite that exploded as a fireball over California's Sierra foothills this past spring was among the fastest, rarest meteorites known to have hit Earth, and it traveled a highly eccentric orbital route to get here.

An international team of scientists presents these and other findings in a study published Dec. 21, in the journal Science. The 70-member team included nine researchers from UC Davis, along with scientists from the SETI Institute, NASA and other institutions.

The researchers found that the meteorite that fell over Northern California on April 22 was the rarest type known to have hit Earth -- a carbonaceous chondrite. It is composed of cosmic dust and presolar materials that helped form the planets of the solar system.

The scientists learned that the meteorite formed about 4.5 billion years ago. It was knocked off its parent body, which may have been an asteroid or a Jupiter-family comet, roughly 50,000 years ago. That began its journey to Sutter's Mill, the gold discovery site that sparked the California Gold Rush.

As it flew toward Earth, it traveled an eccentric course through the solar system, flying from an orbit close to Jupiter toward the sun, passing by Mercury and Venus, and then flying out to hit Earth.

The high-speed, minivan-sized meteorite entered the atmosphere at about 64,000 miles per hour. The study said it was the fastest, "most energetic" reported meteorite that's fallen since 2008, when an asteroid fell over Sudan.

"If this were a much bigger object, it could have been a disaster," said co-author and UC Davis geology professor Qing-zhu Yin. "This is a happy story in this case. "

Before entering Earth's atmosphere, the meteorite is estimated to have weighed roughly 100,000 pounds. Most of that mass burned away when the meteorite exploded. Scientists and private collectors have recovered about 2 pounds remaining.

UC Davis is 60 miles west of the El Dorado county towns of Coloma and Lotus, where pieces of the meteorite were found on residents' driveways and in local forests and parks.

When the meteorite fell, Yin, whose lab contains some of the country's most specialized equipment to measure the age and composition of meteorites, searched for and collected pieces of the fallen meteorite with students and volunteers. He also led a 35-member subgroup of international researchers to study and share information about the meteorite's mineralogy, internal textures, chemical and isotopic compositions and magnetic properties.

Meteorites like Sutter's Mill are thought to have delivered oceans of water to Earth early in its history. Using neutron-computed tomography, UC Davis researchers helped identify where hydrogen, and therefore water-rich fragments, resides in the meteorite without breaking it open.

For the first time, the Doppler weather radar network helped track the falling carbonaceous chondrite meteorite pieces, aiding scientists in the quick recovery of them, the study reports. Yin expects that the weather radar data in the public domain could greatly enhance and benefit future meteorite recoveries on land.

"For me, the fun of this scientific gold rush is really just beginning," said Yin. "This first report based on the initial findings provides a platform to propel us into more detailed research. Scientists are still finding new and exciting things in Murchison, a similar type of meteorite to Sutter's Mill, which fell in Victoria, Australia, in 1969, the same year Apollo astronauts Neil Armstrong and Buzz Aldrin returned the first lunar samples to the Earth. We will learn a lot more with Sutter's Mill."

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by University of California - Davis.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Rocket burn sets stage for dynamic moon duos' lunar impact

Dec. 16, 2012 — The lunar twins of NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission have each completed a rocket burn that has sealed their fate. The burns modified the orbit of the formation-flying spacecraft. Over the next three days, this new orbit will carry the twins lower and lower over the moon's surface. On Monday afternoon, Dec. 17, at about 2:28 p.m. PST (5:28 p.m. EST), their moon-skimming will conclude when a portion of the lunar surface -- an unnamed mountain near the natural satellite's north pole -- rises higher than their orbital altitude.

The maneuvers began at 7:07 a.m. PST (10:07 a.m. EST) Dec. 14 when the Ebb spacecraft fired its main engines for 55.8 seconds, changing its orbital velocity by 10.3 mph (4.6 meters per second). Sixteen seconds later, still at 7:07 a.m. PST, the Flow spacecraft began its maneuver, executing a burn 55.4 seconds in duration with a resulting change in orbital velocity of 10.3 mph (4.6 meters per second). The spacecraft were named Ebb and Flow by elementary school students in Bozeman, Mont., who won a nationwide contest.

Ebb and Flow are being sent purposely into the lunar surface because their low orbit and low fuel levels preclude further scientific operations.

"NASA wanted to rule out any possibility of our twins hitting the surface anywhere near any of the historic lunar exploration sites like the Apollo landing sites or where the Russian Luna probes touched down," said David Lehman, GRAIL project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Our navigators calculated the odds before this maneuver as about seven in a million. Now, after these two successful rocket firings, there is zero chance."

The unnamed mountain where the two spacecraft will make contact is on the moon's nearside, near its north pole, in the vicinity of a crater named Goldschmidt. Both spacecraft will hit the surface at 3,760 mph (1.7 kilometers per second). No imagery of the impact is expected, because the region will be in shadow at the time.

Both spacecraft have been orbiting the moon since Jan. 1, 2012. The duo's successful primary mission yielded the highest-resolution gravity field map of any celestial body. Future gravity field models developed from data collected during the extended mission will be of even higher resolution. The map will provide a better understanding of how the moon, Earth and other rocky planets in the solar system formed and evolved.

JPL manages the GRAIL mission for NASA's Science Mission Directorate in Washington. The mission is part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems in Denver built the spacecraft.

For more information about GRAIL, visit: http://www.nasa.gov/grail

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by NASA/Jet Propulsion Laboratory.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Spacecraft monitoring Martian dust storm

Nov. 21, 2012 — A Martian dust storm that NASA's Mars Reconnaissance Orbiter has been tracking since last week has also produced atmospheric changes detectable by rovers on Mars.

Using the orbiter's Mars Color Imager, Bruce Cantor of Malin Space Science Systems, San Diego, began observing the storm on Nov. 10, and subsequently reported it to the team operating NASA's Mars Exploration Rover Opportunity. The storm came no closer than about 837 miles (1,347 kilometers) from Opportunity, resulting in only a slight drop in atmospheric clarity over that rover, which does not have a weather station.

Halfway around the planet from Opportunity, the NASA Mars rover Curiosity's weather station has detected atmospheric changes related to the storm. Sensors on the Rover Environmental Monitoring Station (REMS), which was provided for Curiosity by Spain, have measured decreased air pressure and a slight rise in overnight low temperature.

"This is now a regional dust storm. It has covered a fairly extensive region with its dust haze, and it is in a part of the planet where some regional storms in the past have grown into global dust hazes," said Rich Zurek, chief Mars scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "For the first time since the Viking missions of the 1970s, we are studying a regional dust storm both from orbit and with a weather station on the surface."

Curiosity's equatorial location and the sensors on REMS, together with the daily global coverage provided by the Mars Reconnaissance Orbiter, provide new advantages compared with what Viking offered with its combination of orbiters and landers. The latest weekly Mars weather report from the orbiter's Mars Color Imager is at http://www.msss.com/msss_images/2012/11/21/ .

Each Martian year lasts about two Earth years. Regional dust storms expanded and affected vast areas of Mars in 2001 and 2007, but not between those years nor since 2007.

"One thing we want to learn is why do some Martian dust storms get to this size and stop growing, while others this size keep growing and go global," Zurek said.

From decades of observing Mars, scientists know there is a seasonal pattern to the largest Martian dust-storm events. The dust-storm season began just a few weeks ago, with the start of southern-hemisphere spring.

Starting on Nov. 16, the Mars Climate Sounder instrument on the Mars Reconnaissance Orbiter detected a warming of the atmosphere at about 16 miles (25 kilometers) above the storm. Since then, the atmosphere in the region has warmed by about 45 degrees Fahrenheit (25 degrees Celsius). This is due to the dust absorbing sunlight at that height, so it indicates the dust is being lofted well above the surface and the winds are starting to create a dust haze over a broad region.

Warmer temperatures are seen not only in the dustier atmosphere in the south, but also in a hot spot near northern polar latitudes due to changes in the atmospheric circulation. Similar changes affect the pressure measured by Curiosity even though the dust haze is still far away.

Besides the research value in better understanding storm behavior, monitoring the storm is also important for Mars rover operations. If the storm were to go global, the Opportunity rover would be affected most. More dust in the air or falling onto its solar panels would reduce the solar-powered rover's energy supply for daily operations. Curiosity is powered by a radioisotope thermoelectric generator, rather than solar cells. The main effects of increased dust in the air at its site would be haze in images and increased air temperature.

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Reconnaissance Orbiter Project and both of the Mars rover projects for NASA's Science Mission Directorate, Washington.

For more information about the missions of NASA's Mars Exploration Program, visit http://marsprogram.jpl.nasa.gov/ .

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by NASA/Jet Propulsion Laboratory.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Have Venusian volcanoes been caught in the act?

Dec. 3, 2012 — Six years of observations by the European Space Agency's Venus Express have shown large changes in the sulphur dioxide content of the planet's atmosphere, and one intriguing possible explanation is volcanic eruptions.

The thick atmosphere of Venus contains over a million times as much sulphur dioxide as Earth's, where almost all of the pungent, toxic gas is generated by volcanic activity.

Most of the sulphur dioxide on Venus is hidden below the planet's dense upper cloud deck, because the gas is readily destroyed by sunlight.

That means any sulphur dioxide detected in Venus' upper atmosphere above the cloud deck must have been recently supplied from below.

Venus is covered in hundreds of volcanoes, but whether they remain active today is much debated, providing an important scientific goal for Venus Express.

The mission has already found clues pointing to volcanism on geologically recent timescales, within the last few hundreds of thousands to millions of years.

A previous analysis of infrared radiation from the surface pointed to lava flows atop a volcano with a composition distinct from those of their surroundings, suggesting that the volcano had erupted in the planet's recent past.

Now, an analysis of sulphur dioxide concentration in the upper atmosphere over six years provides another clue.

Immediately after arriving at Venus in 2006, the spacecraft recorded a significant increase in the average density of sulphur dioxide in the upper atmosphere, followed by a sharp decrease to values roughly ten times lower by today.

A similar fall was also seen during NASA's Pioneer Venus mission, which orbited the planet from 1978 to 1992.

At that time, the preferred explanation was an earlier injection of sulphur dioxide from one or more volcanoes, with Pioneer Venus arriving in time for the decline.

"If you see a sulphur dioxide increase in the upper atmosphere, you know that something has brought it up recently, because individual molecules are destroyed there by sunlight after just a couple of days," says Dr Emmanuel Marcq of Laboratoire Atmosphères, Milieux, Observations Spatiales, France, and lead author of the paper published in Nature Geoscience.

"A volcanic eruption could act like a piston to blast sulphur dioxide up to these levels, but peculiarities in the circulation of the planet that we don't yet fully understand could also mix the gas to reproduce the same result," adds co-author Dr Jean-Loup Bertaux, Principal Investigator for the instrument on Venus Express that made the detections.

Venus has a 'super-rotating' atmosphere that whips around the planet in just four Earth-days, much faster than the 243 days the planet takes to complete one rotation about its axis.

Such rapid atmospheric circulation spreads the sulphur dioxide around, making it difficult to isolate any individual points of origin for the gas.

Dr Marcq's team speculate that if volcanism was responsible for the initial increase, then it could come from a relatively gentle increased output of several active volcanoes rather than one dramatic eruption.

"Alternatively, and taking into account the similar trend observed by Pioneer Venus, it's possible that we are seeing decadal-scale variability in the circulation of the atmosphere, which is turning out to be even more complex than we could ever have imagined," he notes.

"By following clues left by trace gases in the atmosphere, we are uncovering the way Venus works, which could point us to the smoking gun of active volcanism," adds Håkan Svedhem, ESA's Project Scientist for Venus Express.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by European Space Agency (ESA).

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Emmanuel Marcq, Jean-Loup Bertaux, Franck Montmessin, Denis Belyaev. Variations of sulphur dioxide at the cloud top of Venus’s dynamic atmosphere. Nature Geoscience, 2012; DOI: 10.1038/ngeo1650

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Fostering Curiosity: Mars Express relays rocky images

Nov. 26, 2012 — For the first time, ESA's Mars orbiter has relayed scientific data from NASA's Curiosity rover on the Red Planet's surface. The data included detailed images of 'Rocknest3' and were received by ESA's deep-space antenna in Australia.

It was a small but significant step in interplanetary cooperation between space agencies.

Early on the morning of 6 October, ESA's Mars Express looked down as it orbited the planet, lining up its lander communication antenna to point at Curiosity far below on the surface.

For 15 minutes, the NASA rover transmitted scientific data up to the ESA satellite. A few hours later, Mars Express slewed to point its high-gain antenna toward Earth and began downlinking the precious information to the European Space Operations Centre in Darmstadt, Germany, via the Agency's 35 m-diameter antenna in New Norcia, Australia.

The data were immediately made available to NASA's Jet Propulsion Laboratory in California for processing and analysis, proving again that NASA's amazing new rover can talk with Europe's veteran Mars orbiter.

Curiosity's ChemCam images Rocknest3

The information included a tremendously interesting image acquired on 4 October by Curiosity's ChemCam Remote Micro-Imager camera.

ChemCam comprises the camera together with a Laser-Induced Breakdown Spectrometer, which fires a laser at targets and analyses the chemical composition of the vaporised material.

The laser zaps areas smaller than 1 mm across on the surface of martian rocks and soils, and then the spectrometer provides information on the minerals and microstructures in the rocks.

"The quality of these images from ChemCam is outstanding, and the mosaic image of the spectrometer analyses has been essential for scientific interpretation of the data," says Sylvestre Maurice, Deputy Principal Investigator for ChemCam at France's Research Institute in Astrophysics and Planetology (IRAP).

"This combination of imaging and analysis has demonstrated its potential for future missions."

ChemCam laser targets

A third image, relayed separately by NASA, indicates the locations of the laser target points on Rocknest3, as seen by the RMI camera.

'Rocknest' is the area where Curiosity stopped for a month to perform its first mobile laboratory analyses on soil scooped from a small sand dune. Rocknest3 was a convenient nearby target where ChemCam made more than 30 observations using 1500 laser shots.

A wide-angle context image was acquired by Curiosity's MastCam and shows Rocknest3 as targeted by ChemCam. Rocknest3 is about 10 x 40 cm, or roughly the size of a shoe box.

Fostering Curiosity -- and others

ESA's Mars orbiter has also relayed data for NASA's other surface missions -- Phoenix, Spirit and Opportunity -- since 2004, and it relayed Curiosity's radio signal during its arrival at Mars last August.

During the Curiosity mission, Mars Express is set to provide additional relay slots, while maintaining its own scientific observation programme, under an ESA-NASA support agreement.

It can also rapidly provide relay services in case of unavailability of NASA's own relay orbiter or if there is a problem on the rover itself.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by European Space Agency (ESA).

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

NASA's GRAIL lunar impact site named for astronaut Sally Ride

Dec. 17, 2012 — NASA has named the site where twin agency spacecraft impacted the moon Monday in honor of the late astronaut Sally K. Ride, who was America's first woman in space and a member of the probes' mission team.

Last Friday, Ebb and Flow, the two spacecraft comprising NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission, were commanded to descend into a lower orbit that would result in an impact Monday on a mountain near the moon's north pole. The formation-flying duo hit the lunar surface as planned at 2:28:51 p.m. PST (5:28:51 p.m. EST) and 2:29:21 p.m. PST (5:29:21 p.m. EST) at a speed of 3,760 mph (1.7 kilometers per second). The location of the Sally K. Ride Impact Site is on the southern face of an approximately 1.5-mile-tall (2.5-kilometer) mountain near a crater named Goldschmidt.

"Sally was all about getting the job done, whether it be in exploring space, inspiring the next generation, or helping make the GRAIL mission the resounding success it is today," said GRAIL principal investigator Maria Zuber of the Massachusetts Institute of Technology in Cambridge. "As we complete our lunar mission, we are proud we can honor Sally Ride's contributions by naming this corner of the moon after her."

The impact marked a successful end to the GRAIL mission, which was NASA's first planetary mission to carry cameras fully dedicated to education and public outreach. Ride, who died in July after a 17-month battle with pancreatic cancer, led GRAIL's MoonKAM (Moon Knowledge Acquired by Middle School Students) Program through her company, Sally Ride Science, in San Diego.

Along with its primary science instrument, each spacecraft carried a MoonKAM camera that took more than 115,000 total images of the lunar surface. Imaging targets were proposed by middle school students from across the country and the resulting images returned for them to study. The names of the spacecraft were selected by Ride and the mission team from student submissions in a nationwide contest.

"Sally Ride worked tirelessly throughout her life to remind all of us, especially girls, to keep questioning and learning," said Sen. Barbara Mikulski of Maryland. "Today her passion for making students part of NASA's science is honored by naming the impact site for her."

Fifty minutes prior to impact, the spacecraft fired their engines until the propellant was depleted. The maneuver was designed to determine precisely the amount of fuel remaining in the tanks. This will help NASA engineers validate computer models to improve predictions of fuel needs for future missions.

"Ebb fired its engines for 4 minutes 3 seconds, and Flow fired its for 5 minutes 7 seconds," said GRAIL project manager David Lehman of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It was one final important set of data from a mission that was filled with great science and engineering data."

The mission team deduced that much of the material aboard each spacecraft was broken up in the energy released during the impacts. Most of what remained probably is buried in shallow craters. The craters' size may be determined when NASA's Lunar Reconnaissance Orbiter returns images of the area in several weeks.

Launched in September 2011, Ebb and Flow had been orbiting the moon since Jan. 1, 2012. The probes intentionally were sent into the lunar surface because they did not have sufficient altitude or fuel to continue science operations. Their successful prime and extended science missions generated the highest-resolution gravity field map of any celestial body. The map will provide a better understanding of how Earth and other rocky planets in the solar system formed and evolved.

"We will miss our lunar twins, but the scientists tell me it will take years to analyze all the great data they got, and that is why we came to the moon in the first place," Lehman said. "So long, Ebb and Flow, and we thank you." JPL manages the GRAIL mission for NASA's Science Mission Directorate in Washington. GRAIL is part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems in Denver built the spacecraft.

Join the conversation on Twitter by following the hashtag #GRAIL. To learn more about all the ways to connect and collaborate with NASA, visit: http://www.nasa.gov/connect .

For the mission's press kit and other information about GRAIL, visit: http://www.nasa.gov/grail . You can follow JPL News on Facebook at: http://www.facebook.com/nasajpl and on Twitter at: http://www.twitter.com/nasajpl .

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by NASA/Jet Propulsion Laboratory.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Cassini spots mini Nile River on Saturn's moon Titan

Dec. 12, 2012 — Scientists with NASA's Cassini mission have spotted what appears to be a miniature, extraterrestrial likeness of Earth's Nile River: a river valley on Saturn's moon Titan that stretches more than 200 miles (400 kilometers) from its "headwaters" to a large sea. It is the first time images have revealed a river system this vast and in such high resolution anywhere other than Earth.

Scientists deduce that the river, which is in Titan's north polar region, is filled with liquid hydrocarbons because it appears dark along its entire length in the high-resolution radar image, indicating a smooth surface.

"Though there are some short, local meanders, the relative straightness of the river valley suggests it follows the trace of at least one fault, similar to other large rivers running into the southern margin of this same Titan sea," said Jani Radebaugh, a Cassini radar team associate at Brigham Young University, Provo, Utah. "Such faults -- fractures in Titan's bedrock -- may not imply plate tectonics, like on Earth, but still lead to the opening of basins and perhaps to the formation of the giant seas themselves."

The new image is available online at: http://www.nasa.gov/mission_pages/cassini/multimedia/pia16197.html .

Titan is the only other world we know of that has stable liquid on its surface. While Earth's hydrologic cycle relies on water, Titan's equivalent cycle involves hydrocarbons such as ethane and methane. In Titan's equatorial regions, images from Cassini's visible-light cameras in late 2010 revealed regions that darkened due to recent rainfall. Cassini's visual and infrared mapping spectrometer confirmed liquid ethane at a lake in Titan's southern hemisphere known as Ontario Lacus in 2008.

"Titan is the only place we've found besides Earth that has a liquid in continuous movement on its surface," said Steve Wall, the radar deputy team lead, based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "This picture gives us a snapshot of a world in motion. Rain falls, and rivers move that rain to lakes and seas, where evaporation starts the cycle all over again. On Earth, the liquid is water; on Titan, it's methane; but on both it affects most everything that happens."

The radar image here was taken on Sept. 26, 2012. It shows Titan's north polar region, where the river valley flows into Kraken Mare, a sea that is, in terms of size, between the Caspian Sea and the Mediterranean Sea on Earth. The real Nile River stretches about 4,100 miles (6,700 kilometers). The processes that led to the formation of Earth's Nile are complex, but involve faulting in some regions.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and ASI, the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the US and several European countries. JPL is a division of the California Institute of Technology in Pasadena.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by NASA/Jet Propulsion Laboratory.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Mars Curiosity rover explores 'Yellowknife Bay'

Dec. 19, 2012 — The NASA Mars rover Curiosity this week is driving within a shallow depression called "Yellowknife Bay," providing information to help researchers choose a rock to drill.

Using Curiosity's percussive drill to collect a sample from the interior of a rock, a feat never before attempted on Mars, is the mission's priority for early 2013. After the powdered-rock sample is sieved and portioned by a sample-processing mechanism on the rover's arm, it will be analyzed by instruments inside Curiosity.

Yellowknife Bay is within a different type of terrain from what the rover has traversed since landing inside Mars' Gale Crater on Aug. 5, PDT (Aug. 6, UTC). The terrain Curiosity has entered is one of three types that intersect at a location dubbed "Glenelg," chosen as an interim destination about two weeks after the landing.

Curiosity reached the lip of a 2-foot (half-meter) descent into Yellowknife Bay with a 46-foot (14-meter) drive on Dec. 11. The next day, a drive of about 86 feet (26.1 meters) brought the rover well inside the basin. The team has been employing the Mast Camera (Mastcam) and the laser-wielding Chemistry and Camera (ChemCam) for remote-sensing studies of rocks along the way.

On Dec. 14, Curiosity drove about 108 feet (32.8 meters) to reach rock targets of interest called "Costello" and "Flaherty." Researchers used the Alpha Particle X-Ray Spectrometer (APXS) and Mars Hand Lens Imager (MAHLI) at the end of the rover's arm to examine the targets. After finishing those studies, the rover drove again on Dec. 17, traveling about 18 feet (5.6 meters) farther into Yellowknife Bay. That brings the mission's total driving distance to 0.42 mile (677 meters) since Curiosity's landing.

One additional drive is planned this week before the rover team gets a holiday break. Curiosity will continue studying the Martian environment from its holiday location at the end point of that drive within Yellowknife Bay. The mission's plans for most of 2013 center on driving toward the primary science destination, a 3-mile-high (5-kilometer) layered mound called Mount Sharp.

NASA's Mars Science Laboratory Project is using Curiosity during a two-year prime mission to assess whether areas inside Gale Crater ever offered a habitable environment for microbes. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the project for NASA's Science Mission Directorate in Washington.

More information about Curiosity is online at http://www.jpl.nasa.gov/msl , http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ . You can follow the mission on Facebook at: http://www.facebook.com/marscuriosity and on Twitter at: http://www.twitter.com/marscuriosity .

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by NASA/Jet Propulsion Laboratory.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Autumn sets in rapidly on Saturn's giant moon

Nov. 28, 2012 — As leaves fall and winter approaches in Earth's Northern Hemisphere, a change of seasons is also rapidly becoming noticeable in the southern hemisphere of Saturn's giant moon, Titan.

Thanks to NASA's Cassini spacecraft which has been orbiting Saturn since 2004, scientists have been able to observe for the first time ever the seasonal atmospheric circulation direction change on Titan -- an event which only happens once every 15 years and is never observable from Earth. Their findings are published today in Nature.

Titan, while technically only a moon, is bigger than the planet Mercury, and is often considered a planet in its own right. It is the only known moon to have a significant atmosphere and is one of only four terrestrial atmospheres in our Solar System (the other three being Earth, Venus, and Mars). As Titan's rotation axis is tilted by a similar amount to that of Earth, it experiences seasons in a similar way, but at a much more relaxed pace as Saturn takes 29.5 Earth years to orbit the Sun.

Dr Nick Teanby of the University of Bristol and colleagues used infrared spectra measured by Cassini's Composite InfraRed Spectrometer (CIRS) instrument to determine atmospheric temperature and global distributions of chemical tracers. This allowed them to map out the seasonal changes in great detail.

The team observed an enormous increase in Titan's exotic trace gases over the south pole within a relatively short time. These trace gases are produced high in Titan's atmosphere, where sunlight and highly energetic particles break down nitrogen and methane and recombine to form a vast array of more complex molecules like benzene and hydrogen cyanide.

Co-author, Dr Remco de Kok of SRON Netherlands Institute for Space Research said: "We were waiting for signs that the trace gas abundances would change together with the new season, but we did not expect such a large and rapid change: some gas concentrations increased more than a thousand times within only a few months. Also surprising was that this was happening at altitudes above 450 km, much higher than initially anticipated."

At these high altitudes the atmosphere goes around the planet much faster than the rotation of Titan's solid surface and can have horizontal wind speeds around the planet of up to 200m/s (450mph). Vertical winds caused by the seasonally varying hemisphere to hemisphere atmospheric circulation are much slower at a rather sluggish few millimetres per second and are hard to measure using conventional means.

Lead author, Dr Nick Teanby of Bristol's School of Earth Sciences said: "Using measurements of temperature and chemical tracers by Cassini, we were able to observe changes in the subtle vertical winds and reveal the pole-to-pole circulation cell. For the first time ever, we observed the circulation cell direction reverse over the south pole around the time of the 2009 southern autumnal equinox. The resulting distribution of gases shows that the circulation must extend much further than previously thought to 600 km or even higher. This calls into question our current understanding of how Titan's atmosphere works and suggests new avenues to explore."

"Our results provide a powerful new constraint for atmospheric models of Titan. Titan provides a natural laboratory for an Earth-like atmosphere in the cold outer solar system. So, these results could eventually lead to a more complete understanding of atmospheric processes on Earth, other Solar System planets, and the many exoplanetary systems now being discovered."

In the coming years Cassini will continue to observe how the seasons develop. Dr Conor Nixon at NASA Goddard Space Flight Centre said: "These results are giving us the first detailed look at changes occurring in Titan's atmosphere around the time of equinox, a season which has not been viewed up close by a spacecraft previously. This shows the really great science that is coming out of the Cassini extended mission phases since 2008, and we look forward to seeing the further changes that will occur over the next five years until the end of mission in 2017."

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by University of Bristol.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Nicholas A. Teanby, Patrick G. J. Irwin, Conor A. Nixon, Remco de Kok, Sandrine Vinatier, Athena Coustenis, Elliot Sefton-Nash, Simon B. Calcutt, F. Michael Flasar. Active upper-atmosphere chemistry and dynamics from polar circulation reversal on Titan. Nature, 2012; 491 (7426): 732 DOI: 10.1038/nature11611

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Astrophysicists identify a 'super-Jupiter' around massive star

Nov. 19, 2012 — Astrophysicists at the University of Toronto and other institutions across the United States, Europe and Asia have discovered a 'super-Jupiter' around the massive star Kappa Andromedae. The object, which could represent the first new observed exoplanet system in almost four years, has a mass at least 13 times that of Jupiter and an orbit somewhat larger than Neptune's.

The host star around which the planet orbits has a mass 2.5 times that of the Sun, making it the highest mass star to ever host a directly observed planet. The star can be seen with the naked eye in the constellation Andromeda at a distance of about 170 light years.

"Our team identified a faint object located very close to Kappa Andromedae in January that looks much like other young, massive directly imaged planets but does not look like a star," said Thayne Currie, a post-doctoral fellow in the Department of Astronomy & Astrophysics at the University of Toronto and coauthor of a paper titled "Direct imaging of a `super-Jupiter' around a massive star" to be published in the Astrophysical Journal Letters. "It's likely a directly imaged planet."

The researchers made the discovery based on an infrared imaging search carried out as part of the Strategic Explorations of Exoplanets and Disks with Subaru (SEEDS) program using the Subaru telescope located in Hawaii.

"Kappa Andromedae moves fast across the sky so it will appear to change position relative to more distant, background objects," Currie says. "When we reobserved it in July at multiple wavelengths, we saw the faint object again, located at about the same position as it was in January. This indicates that it is bound to the star and not an unrelated background object." Labelled by the researchers Kappa And b, it could be the first direct rendering of an exoplanet in two years and of a new exoplanet system in almost four years, ending a significant drought in the field.

In a single infrared snapshot, the tiny point of light that is Kappa And b is completely lost amid the overwhelming glare of the host star. The SEEDS observing team was able to distinguish the object's faint light using a technique known as angular differential imaging, which combines a time-series of individual images in a manner that allows for the otherwise overwhelming glare of the host star to be removed from the final, combined image.

Young planets retain significant heat from their formation, enhancing the brightness at infrared wavelengths. This makes young star systems attractive targets for direct imaging planet searches. However, despite this fact, the successful direct imaging of extrasolar planets is exceptionally rare, especially for orbital separations akin to our own solar system planets. The extraordinary differences in brightness between a star and a planet are a primary reason why only a handful of planets have ever been directly imaged around stars.

"Although astronomers have found over 750 planets around other stars, we actually directly detect light from the atmosphere of only a few of them," said Currie. "There are approximately six now. Kappa And b is one of them if our estimates for its age and mass are correct, which we think they are. The rest are only inferred directly."

The large mass of both the host star and gas giant provide a sharp contrast with our own solar system. Observers and theorists have argued recently that large stars like Kappa Andromedae are likely to have large planets, perhaps following a simple scaled-up model of our own solar system. But experts predict that there is a limit to such extrapolations; if a star is too massive, its powerful radiation may disrupt the normal planet formation process that would otherwise occur. The discovery of the super-Jupiter around Kappa Andromedae demonstrates that stars as large as 2.5 solar masses are still fully capable of producing planets within their primordial circumstellar disks.

"This planetary system is very different from our own," Currie says. "The star is much more massive than our Sun and Kappa And b is at least 10 times more massive than any planet in the solar system. And, Kappa And b is located further from the star than any of the solar system planets are from the Sun. Because it is generally much harder to form massive planets at large distances from the parent star, Kappa And b could really be a challenge for our theories about how planets form."

The SEEDS research team continues to study the Kappa And b emitted light across a broad wavelength range, in order to better understand the atmospheric chemistry of the gas giant, and constrain the orbital characteristics. The researchers also continue to explore the system for possible secondary planets, which may have influenced the Kappa And b formation and orbital evolution. These follow-up studies will yield further clues to the formation of the super-Jupiter, and planet formation in general around massive stars.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by University of Toronto, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

J. Carson, C. Thalmann, M. Janson, T. Kozakis, M. Bonnefoy, B. Biller, J. Schlieder, T. Currie, M. McElwain, M. Goto, T. Henning, W. Brandner, M. Feldt, R. Kandori, M. Kuzuhara, L. Stevens, P. Wong, K. Gainey, M. Fukagawa, Y. Kuwada, T. Brandt, J. Kwon, L. Abe, S. Egner, C. Grady, O. Guyon, J. Hashimoto, Y. Hayano, M. Hayashi, S. Hayashi, K. Hodapp, M. Ishii, M. Iye, G. Knapp, T. Kudo, N. Kusakabe, T. Matsuo, S. Miyama, J. Morino, A. Moro-Martin, T. Nishimura, T. Pyo, E. Serabyn, H. Suto, R. Suzuki, M. Takami, N. Takato, H. Terada, E. Turner, M. Watanabe, J. Wisniewski, T. Yamada, H. Takami, T. Usuda, M. Tamura. Direct Imaging Discovery of a `Super-Jupiter' Around the late B-Type Star Kappa. Astrophysical Journal Letters, 2012; (accepted) [link]

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Do missing Jupiters mean massive comet belts?

Nov. 27, 2012 — Using ESA's Herschel space observatory, astronomers have discovered vast comet belts surrounding two nearby planetary systems known to host only Earth-to-Neptune-mass worlds. The comet reservoirs could have delivered life-giving oceans to the innermost planets.

In a previous Herschel study, scientists found that the dusty belt surrounding nearby star Fomalhaut must be maintained by collisions between comets.

In the new Herschel study, two more nearby planetary systems -- GJ 581 and 61 Vir -- have been found to host vast amounts of cometary debris.

Herschel detected the signatures of cold dust at 200ºC below freezing, in quantities that mean these systems must have at least 10 times more comets than in our own Solar System's Kuiper Belt.

GJ 581, or Gliese 581, is a low-mass M dwarf star, the most common type of star in the Galaxy. Earlier studies have shown that it hosts at least four planets, including one that resides in the 'Goldilocks Zone' -- the distance from the central sun where liquid surface water could exist.

Two planets are confirmed around G-type star 61 Vir, which is just a little less massive than our Sun.

The planets in both systems are known as 'super-Earths', covering a range of masses between 2 and 18 times that of Earth.

Interestingly, however, there is no evidence for giant Jupiter- or Saturn-mass planets in either system.

The gravitational interplay between Jupiter and Saturn in our own Solar System is thought to have been responsible for disrupting a once highly populated Kuiper Belt, sending a deluge of comets towards the inner planets in a cataclysmic event that lasted several million years.

"The new observations are giving us a clue: they're saying that in the Solar System we have giant planets and a relatively sparse Kuiper Belt, but systems with only low-mass planets often have much denser Kuiper belts," says Dr Mark Wyatt from the University of Cambridge, lead author of the paper focusing on the debris disc around 61 Vir.

"We think that may be because the absence of a Jupiter in the low-mass planet systems allows them to avoid a dramatic heavy bombardment event, and instead experience a gradual rain of comets over billions of years."

"For an older star like GJ 581, which is at least two billion years old, enough time has elapsed for such a gradual rain of comets to deliver a sizable amount of water to the innermost planets, which is of particular importance for the planet residing in the star's habitable zone," adds Dr Jean-Francois Lestrade of the Observatoire de Paris who led the work on GJ 581.

However, in order to produce the vast amount of dust seen by Herschel, collisions between the comets are needed, which could be triggered by a Neptune-sized planet residing close to the disc.

"Simulations show us that the known close-in planets in each of these systems cannot do the job, but a similarly-sized planet located much further from the star -- currently beyond the reach of current detection campaigns -- would be able to stir the disc to make it dusty and observable," says Dr Lestrade.

"Herschel is finding a correlation between the presence of massive debris discs and planetary systems with no Jupiter-class planets, which offers a clue to our understanding of how planetary systems form and evolve," says Göran Pilbratt, ESA's Herschel project scientist.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by European Space Agency (ESA).

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal References:

M. C. Wyatt, G. Kennedy, B. Sibthorpe, A. Moro-Martín, J.-F. Lestrade, R. J. Ivison, B. Matthews, S. Udry, J. S. Greaves, P. Kalas, S. Lawler, K. Y. L. Su, G. H. Rieke, M. Booth, G. Bryden, J. Horner, J. J. Kavelaars, D. Wilner. Herschel imaging of 61 Vir: implications for the prevalence of debris in low-mass planetary systems. Monthly Notices of the Royal Astronomical Society, 2012; 424 (2): 1206 DOI: 10.1111/j.1365-2966.2012.21298.xJ.-F. Lestrade et al. A DEBRIS disk around the planet hosting M-star GJ 581 spatially resolved with Herschel. Astronomy & Astrophysics, (accepted)

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Complex chemistry within the Martian soil: No definitive detection of organics yet

Dec. 3, 2012 — NASA's Mars Curiosity rover has used its full array of instruments to analyze Martian soil for the first time, and found a complex chemistry within the Martian soil. Water and sulfur and chlorine-containing substances, among other ingredients, showed up in samples Curiosity's arm delivered to an analytical laboratory inside the rover.

Detection of the substances during this early phase of the mission demonstrates the laboratory's capability to analyze diverse soil and rock samples over the next two years. Scientists also have been verifying the capabilities of the rover's instruments.

Curiosity is the first Mars rover able to scoop soil into analytical instruments. The specific soil sample came from a drift of windblown dust and sand called "Rocknest." The site lies in a relatively flat part of Gale Crater still miles away from the rover's main destination on the slope of a mountain called Mount Sharp. The rover's laboratory includes the Sample Analysis at Mars (SAM) suite and the Chemistry and Mineralogy (CheMin) instrument. SAM used three methods to analyze gases given off from the dusty sand when it was heated in a tiny oven. One class of substances SAM checks for is organic compounds -- carbon-containing chemicals that can be ingredients for life.

"We have no definitive detection of Martian organics at this point, but we will keep looking in the diverse environments of Gale Crater," said SAM Principal Investigator Paul Mahaffy of NASA's Goddard Space Flight Center in Greenbelt, Md.

Curiosity's APXS instrument and the Mars Hand Lens Imager (MAHLI) camera on the rover's arm confirmed Rocknest has chemical-element composition and textural appearance similar to sites visited by earlier NASA Mars rovers Pathfinder, Spirit and Opportunity.

Curiosity's team selected Rocknest as the first scooping site because it has fine sand particles suited for scrubbing interior surfaces of the arm's sample-handling chambers. Sand was vibrated inside the chambers to remove residue from Earth. MAHLI close-up images of Rocknest show a dust-coated crust one or two sand grains thick, covering dark, finer sand.

"Active drifts on Mars look darker on the surface," said MAHLI Principal Investigator Ken Edgett, of Malin Space Science Systems in San Diego."This is an older drift that has had time to be inactive, letting the crust form and dust accumulate on it."

CheMin's examination of Rocknest samples found the composition is about half common volcanic minerals and half non-crystalline materials such as glass. SAM added information about ingredients present in much lower concentrations and about ratios of isotopes. Isotopes are different forms of the same element and can provide clues about environmental changes. The water seen by SAM does not mean the drift was wet. Water molecules bound to grains of sand or dust are not unusual, but the quantity seen was higher than anticipated.

SAM tentatively identified the oxygen and chlorine compound perchlorate. This is a reactive chemical previously found in arctic Martian soil by NASA's Phoenix Lander. Reactions with other chemicals heated in SAM formed chlorinated methane compounds -- one-carbon organics that were detected by the instrument. The chlorine is of Martian origin, but it is possible the carbon may be of Earth origin, carried by Curiosity and detected by SAM's high sensitivity design.

"We used almost every part of our science payload examining this drift," said Curiosity Project Scientist John Grotzinger of the California Institute of Technology in Pasadena. "The synergies of the instruments and richness of the data sets give us great promise for using them at the mission's main science destination on Mount Sharp."

NASA's Mars Science Laboratory Project is using Curiosity to assess whether areas inside Gale Crater ever offered a habitable environment for microbes. NASA's Jet Propulsion Laboratory in Pasadena manages the project for NASA's Science Mission Directorate in Washington.

For more information about Curiosity and other Mars mission, visit: http://www.nasa.gov/mars

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by NASA/Jet Propulsion Laboratory.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Sungrazing comets as solar probes

Dec. 6, 2012 — To observe how winds move high in Earth's atmosphere, scientists sometimes release clouds of barium as tracers to track how the material corkscrews, blows around, and changes composition in response to high altitude winds -- but scientists have no similar technique to study the turbulent atmosphere of the sun.

So researchers were excited in December 2011, when Comet Lovejoy swept right through the sun's corona with its long tail streaming behind it. Several missions -- including NASA's Solar Dynamics Observatory (SDO), NASA's Solar and Terrestrial Relations Observatory (STEREO), ESA/NASA's Solar and Heliospheric Observatory (SOHO) and the JAXA/NASA mission Hinode -- captured images of the comet, showing how its long tail was buffeted by systems around the sun, offering scientists a unique way of observing movement as if they'd orchestrated the experiment themselves.

This unexpected set of observations captured the attention of scientists, bringing two research communities together: comet researchers who can use solar observations for their studies and solar scientists can use comet observations to study the sun.

Scientists recently shared their results at the 2012 Fall American Geophysical Union meeting in San Francisco, Calif., and how the comet helped highlight the intensely dynamic environment in the sun's atmosphere, the corona. Since comet tails are rapidly ionized by losing electrons in that hot environment, their movement is affected by the sun's magnetic field. Thus the tail's path can act as a tracer of the complex magnetic system higher up in the corona. Understanding such magnetic systems is a crucial part of space weather research and the study of how magnetic energy is converted to giant explosions on the sun such as solar flares or coronal mass ejections.

Comet Lovejoy is a kind of comet known as a sungrazer, which swings particularly close to the sun. Since SOHO launched in1995, it has shown us thousands more sungrazer comets than any tool ever has before -- almost 2,400 comets as of November 2012. Because we are in a period of high sun grazing comet activity, scientist's can expect many more chances to watch these natural research satellites in the coming years. Another large comet is expected to have a close solar pass on November 21, 2013. This comet is roughly the size of Hale-Bopp, so it should give quite a show.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by NASA.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Could astronauts use a 3-D printer to make parts from moon rocks?

Nov. 28, 2012 — Imagine landing on the moon or Mars, putting rocks through a 3-D printer and making something useful -- like a needed wrench or replacement part.

"It sounds like science fiction, but now it's really possible," says Amit Bandyopadhyay, professor in the School of Mechanical and Materials Engineering at Washington State University.

Bandyopadhyay and a group of colleagues recently published a paper in Rapid Prototyping Journal demonstrating how to print parts using materials from the moon.

Bandyopadhyay and Susmita Bose, professor in the School of Mechanical and Materials Engineering, are well known researchers in the area of three-dimensional printing, creating bone-like materials for orthopedic implants.

In 2010, researchers from NASA initiated discussion with Bandyopadhyay, asking if their research team might be able to print 3-D objects from moon rock. Because of the tremendous expense of space travel, researchers strive to limit what space ships have to carry. Establishment of a lunar or Martian outpost would require using the materials that are on hand for construction or repairs. That's where the 3-D fabrication technology might come in.

Three-dimensional fabrication technology, also known as additive manufacturing, allows researchers to produce complex three dimensional objects directly from computer-aided design (CAD) models, printing the material layer by layer. In this case, the material is heated using a laser to high temperatures and prints out like melting candle wax to a desired shape.

To test the idea, NASA researchers provided Bandyopadhyay and Bose with 10 pounds of raw lunar regolith simulant, an imitation moon rock that is used for research purposes.

The WSU researchers were concerned about how the moon rock material, which is made of silicon, aluminum, calcium, iron and magnesium oxides, would melt, but they found it behaved similarly to silica. And, they built a few simple shapes.

The researchers are the first to demonstrate the ability to fabricate parts using the moon-like material. They sent their pieces to NASA.

"It doesn't look fantastic, but you can make something out of it," says Bandyopadhyay.

Using additive manufacturing, the material could also be tailored, the researchers say. If you want a stronger building material, for instance, you could perhaps use some moon rock with earth-based additives.

"The advantage of additive manufacturing is that you can control the composition as well as the geometry," says Bose. In the future, the researchers hope to show that the lunar material could be used to do remote repairs.

"It is an exciting science fiction story, but maybe we'll hear about it in the next few years," says Bandyopadhyay. "As long as you can have additive manufacturing set up, you may be able to scoop up and print whatever you want. It's not that far-fetched."

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by Washington State University, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Vamsi Krishna Balla et al. First demonstration on direct laser fabrication of lunar regolith parts. Rapid Prototyping Journal, 2012; 18 (6): 451 DOI: 10.1108/13552541211271992

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Titan, Saturn's largest moon, icier than thought

Dec. 4, 2012 — Scientists have long suspected that a vast ocean of liquid water lies under the crusty exterior of Titan, Saturn's largest moon. New analysis suggests that the internally generated heat that keeps that ocean from freezing relies on the moon's interactions with Saturn and its other moons.

A new analysis of topographic and gravity data from Titan, the largest of Saturn's moons, indicates that Titan's icy outer crust is twice as thick as has generally been thought.

Scientists have long suspected that a vast ocean of liquid water lies under the crust. The new study suggests that the internally generated heat that keeps that ocean from freezing solid depends far more on Titan's interactions with Saturn and its other moons than had been suspected.

Howard Zebker, a professor of geophysics and of electrical engineering at Stanford University, will present the findings at the annual meeting of the American Geophysical Union (AGU) in San Francisco on Dec. 4.

Zebker is part of the team interpreting radar data of Titan acquired by NASA's Cassini spacecraft, which has been orbiting Saturn since 2004. He has been studying the topography of Titan, and has combined improved radar measurements of the moon's surface with newly released gravity measurements to make the new analysis.

Titan has long intrigued scientists because of its similarities to Earth. Like Earth, Titan appears to have a layered structure, crudely similar to the concentric layers of an onion, albeit far less edible.

"Titan probably has a core that is a mixture of ice and rock," said Zebker. The core is overlain by the ocean and icy crust.

The rock in the core is thought to contain radioactive elements left over from the formation of the solar system. As in Earth's core, when those elements decay, they generate heat. On Titan, that heat is crucial to keeping its ocean from freezing solid.

As Titan orbits Saturn, Titan is slowly spinning on its axis, one spin for each trip around Saturn. Still, that spin is enough for the gravity instrument onboard Cassini to measure the resistance of Titan to any changes in its spin -- also called the moment of inertia.

"The moment of inertia depends essentially on the thickness of the layers of material within Titan," Zebker said. Thus, he and his graduate students were able to use that data to calculate the moon's internal structure.

"The picture of Titan that we get has an icy, rocky core with a radius of a little over 2,000 kilometers, an ocean somewhere in the range of 225 to 300 kilometers thick and an ice layer that is 200 kilometers thick," he said.

Previous models of Titan's structure estimated the icy crust to be approximately 100 kilometers thick. So if there is more ice, then there should be less heat from the core than had been estimated. One way to account for less heat being generated internally is for there to be less rock and more ice in the core than previous models had predicted.

That all seems simple enough, but there is a complication. Titan is not a true sphere. Its shape is distorted by the gravitational pull of Saturn, making the moon sort of oblong along its equator and a little flattened at the poles.

From measurements of the observed gravitational field of Titan, one can compute what the shape of Titan ought to be. But the new data show that Titan's shape is much more distorted than would be predicted by a simple gravitational model.

That discrepancy means the internal structure of Titan isn't quite so simple.

For Titan to exert its observed gravitational pull, the average density from any given point on the moon down to the center of the core has to be the same, said Zebker.

But that's not the case, since Titan is somewhat squashed. For the data to line up, the density of material under the poles must be slightly greater than it is under the equator.

Since liquid water is denser than ice, Zebker's team reasoned that the ice layer must be slightly thinner at the poles than at the core, and the layer of water correspondingly thicker.

The team members calculated that the thickness of the icy crust is about 3,000 meters less than average at the poles and 3,000 meters greater than average at the equator. And the combination of gravity and topography further suggests that the average thickness of the icy layer is about 200 km.

For the icy crust to vary in thickness across Titan's surface, the heat distribution within the moon must vary as well. But that variation is not likely to come from the moon's core -- heat generated there would be fairly uniform in all directions.

Zebker said the variation in ice thickness could be a result of variation in the shape of Titan's orbit around Saturn, which is not perfectly circular.

"The variation in the shape of the orbit, along with Titan's slightly distorted shape, means that there is some flexure within the moon as it orbits Saturn," said Zebker. The planet's other moons also exert some tidal influence on Titan as they all follow their different orbits, but the primary tidal influence is Saturn.

"The tides move around a little as Titan orbits and if you move anything, you generate a little bit of heat."

For example, if you take a thin strip of metal and flex it, it will begin to weaken and eventually you can break it. That weakening is the result of heat being generated as you flex the metal.

The tidal interactions tend to be more concentrated at the poles than the equator, which means that there is slightly more heat generated at the poles, which in turn melts a little bit of ice at the bottom of the ice layer, thinning the ice in that region in comparison to other parts of the planet, Zebker said.

The Cassini mission was recently given funding to continue operating through 2017, which means about five more years of data will be acquired that can contribute to further refinements of Zebker's model of Titan.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by Stanford University. The original article was written by Louis Bergeron.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

NASA rover providing new weather and radiation data about Mars

Nov. 15, 2012 — Observations of wind patterns and natural radiation patterns on Mars by NASA's Curiosity rover are helping scientists better understand the environment on the Red Planet's surface.

Researchers using the car-sized mobile laboratory have identified transient whirlwinds, mapped winds in relation to slopes, tracked daily and seasonal changes in air pressure, and linked rhythmic changes in radiation to daily atmospheric changes. The knowledge being gained about these processes helps scientists interpret evidence about environmental changes on Mars that might have led to conditions favorable for life.

During the first 12 weeks after Curiosity landed in an area named Gale Crater, an international team of researchers analyzed data from more than 20 atmospheric events with at least one characteristic of a whirlwind recorded by the Rover Environmental Monitoring Station (REMS) instrument. Those characteristics can include a brief dip in air pressure, a change in wind direction, a change in wind speed, a rise in air temperature or a dip in ultraviolet light reaching the rover. Two of the events included all five characteristics.

In many regions of Mars, dust-devil tracks and shadows have been seen from orbit, but those visual clues have not been seen in Gale Crater. One possibility is that vortex whirlwinds arise at Gale without lifting as much dust as they do elsewhere.

"Dust in the atmosphere has a major role in shaping the climate on Mars," said Manuel de la Torre Juarez of NASA's Jet Propulsion Laboratory in Pasadena, Calif. He is the investigation scientist for REMS, which Spain provided for the mission. "The dust lifted by dust devils and dust storms warms the atmosphere."

Dominant wind direction identified by REMS has surprised some researchers who expected slope effects to produce north-south winds. The rover is just north of a mountain called Mount Sharp. If air movement up and down the mountain's slope governed wind direction, dominant winds generally would be north-south. However, east-west winds appear to predominate. The rim of Gale Crater may be a factor.

"With the crater rim slope to the north and Mount Sharp to the south, we may be seeing more of the wind blowing along the depression in between the two slopes, rather than up and down the slope of Mount Sharp," said Claire Newman, a REMS investigator at Ashima Research in Pasadena. "If we don't see a change in wind patterns as Curiosity heads up the slope of Mount Sharp -- that would be a surprise."

REMS monitoring of air pressure has tracked both a seasonal increase and a daily rhythm. Neither was unexpected, but the details improve understanding of atmospheric cycles on present-day Mars, which helps with estimating how the cycles may have operated in the past.

The seasonal increase results from tons of carbon dioxide, which had been frozen into a southern winter ice cap, returning into the atmosphere as southern spring turns to summer. The daily cycle of higher pressure in the morning and lower pressure in the evening results from daytime heating of the atmosphere by the sun. As morning works its way westward around the planet, so does a wave of heat-expanded atmosphere, known as a thermal tide.

Effects of that atmospheric tide show up in data from Curiosity's Radiation Assessment Detector (RAD). This instrument monitors high-energy radiation considered to be a health risk to astronauts and a factor in whether microbes could survive on Mars' surface.

"We see a definite pattern related to the daily thermal tides of the atmosphere," said RAD Principal Investigator Don Hassler of the Southwest Research Institute's Boulder, Colo., branch. "The atmosphere provides a level of shielding, and so charged-particle radiation is less when the atmosphere is thicker. Overall, Mars' atmosphere reduces the radiation dose compared to what we saw during the flight to Mars."

The overall goal of NASA's Mars Science Laboratory mission is to use 10 instruments on Curiosity to assess whether areas inside Gale Crater ever offered a habitable environment for microbes.

JPL, a division of the California Institute of Technology in Pasadena, manages the project for NASA's Science Mission Directorate, Washington, and built Curiosity.

For more information about Curiosity and its mission, visit: http://www.jpl.nasa.gov/msl , http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl .

You can follow the mission on Facebook and Twitter at: http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity .

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by NASA/Jet Propulsion Laboratory.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Meteorites reveal warm water existed on Mars

Nov. 15, 2012 — Hydrothermal fractures around Martian impact craters may have been a habitable environment for microbial life.

New research by the University of Leicester and The Open University into evidence of water on Mars, sufficiently warm enough to support life, has been published this week in the journal Earth and Planetary Science Letters.

The study determined that water temperatures on the Red Planet ranged from 50°C to 150°C. Microbes on Earth can live in similar waters, for example in the volcanic thermal springs at Yellowstone Park, the scientists behind the research point out.

The research is based on detailed scrutiny of Mars meteorites on Earth using powerful microscopes in the University of Leicester Department of Physics and Astronomy. This was followed-up by computer modeling work at The Open University.

Dr John Bridges, Reader in Planetary Science in the University of Leicester Space Research Centre and Lead Author, said: "Rovers on Mars -- the Mars Exploration rovers Spirit and Opportunity, and the Mars Science Laboratory rover Curiosity -- are studying rocks to find out about the geologic history of the Red Planet. Some of the most interesting questions are what we can find out about water, how much there was and what temperature it might have had.

"While the orbiters and rovers are studying the minerals on Mars, we also have meteorites from Mars here on Earth. They come in three different groups, the shergottites, the nakhlites and the chassignites. Of most interest for the question of water on Mars are the nakhlites, because this group of Martian meteorites contains small veins, which are filled with minerals formed by the action of water near the surface of Mars."

Dr. Bridges and his group studied those alteration minerals in great detail. Altogether eight nakhlite Martian meteorites are known, and all have small but significant differences between them and in their alteration minerals.

Lafayette is one of them; and the most complete succession of newly formed minerals can be found in its veins. Careful investigations of the minerals with an electron microscope and a transmission electron microscope have revealed that the first newly formed mineral to grow along the walls of the vein was iron carbonate. The carbonate would have been formed by CO2-rich water around 150°C. When the water cooled to 50°C, it would have formed the clay minerals, which were then followed by an amorphous phase that has the same composition as the clay.

Microbes use the reactions during mineral formation to gain energy and elements essential for their survival.

Dr Bridges added: "The mineralogical details we see tell us that there had been high carbon dioxide pressure in the veins to form the carbonates. Conditions then changed to less carbon dioxide in the fluid and clay minerals formed. We have a good understanding of the conditions minerals form in but to get to the details, chemical models are needed."

Dr Susanne Schwenzer, Postdoctoral Research Associate in the Department of Physical Sciences at The Open University who previously studied Martian meteorite compositions, said: "Until John's study was finished, I used the findings from orbiters around Mars, and modelled each of the new minerals individually. Those orbiters have found clays on the surface of Mars, but the spatial resolution is very different from the detailed study achieved in the nakhlites. Before we had the detailed study of the nakhlite meteorites, we did not know that carbonates are forming first, followed by the clays. Therefore I was very excited to see the details of the new mineralogical study."

By combining data from both universities, researchers were able to predict water conditions on Mars. Initially, the water was around 150°C and contained a lot of CO2, forming the carbonates, then cooled to about 50°C, thus forming the clays.

"The driving force heating the water might have been an impact into the Martian surface." Dr. Bridges explains. "And you only have to look at a map of Mars to see how numerous those are on the Martian surface," Dr. Schwenzer adds.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by University of Leicester.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

J.C. Bridges, S.P. Schwenzer. The nakhlite hydrothermal brine on Mars. Earth and Planetary Science Letters, 2012; 359-360: 117 DOI: 10.1016/j.epsl.2012.09.044

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Orbiter spies where rover's cruise stage hit Mars

Dec. 6, 2012 — During the 10 minutes before the NASA Mars Science Laboratory spacecraft entered the Martian atmosphere to deliver the rover Curiosity to the surface, the spacecraft shed its cruise stage, which had performed vital functions during the flight from Earth, and then jettisoned two 165-pound (75-kilogram) blocks of tungsten to gain aerodynamic lift.

Cameras on the NASA Mars Reconnaissance Orbiter have imaged impact scars where the tungsten blocks and the broken-apart cruise stage hit about 50 miles (80 kilometers) west of where Curiosity landed on Aug. 5, 2012, PDT (Aug. 6, UTC).

The images from the orbiter's High Resolution Imaging Science Experiment (HiRISE) camera are online at http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA16456 .

Although hundreds of new impact sites have been imaged on Mars, researchers do not get independent information about the initial size, velocity, density, strength, or impact angle of the objects. For the Mars Science Laboratory hardware, such information is known, so study of this impact field will provide information on impact processes and Mars surface and atmospheric properties.

The Mars Reconnaissance Orbiter has been examining Mars with six science instruments since 2006. Now in an extended mission, the orbiter continues to provide insights about the planet's ancient environments and about how processes such as wind, meteorite impacts and seasonal frosts are continuing to affect the Martian surface today. This mission has returned more data about Mars than all other orbital and surface missions combined.

More than 27,000 images taken by HiRISE are available for viewing on the instrument team's website: http://hirise.lpl.arizona.edu . Each observation by this telescopic camera covers several square miles, or square kilometers, and can reveal features as small as a desk.

HiRISE is operated by the University of Arizona, Tucson. The instrument was built by Ball Aerospace & Technologies Corp., Boulder, Colo. The Mars Reconnaissance Orbiter project is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate, Washington. JPL is a division of the California Institute of Technology, also in Pasadena. Lockheed Martin Space Systems, Denver, built the spacecraft.

For more information about the Mars Reconnaissance Orbiter, see: www.nasa.gov/mro .

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by NASA/Jet Propulsion Laboratory.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Robotic explorers may usher in lunar 'water rush'

Nov. 15, 2012 — The American space program stands at the cusp of a "water rush" to the moon by several companies developing robotic prospectors for launch in the near future, according to a NASA scientist considering how to acquire and use water ice believed to be at the poles of the moon.

"This is like the gold rush that led to the settlement of California," said Phil Metzger, a physicist who leads the Granular Mechanics and Regolith Operations Lab, part of Kennedy's Surface Systems Office. "This is the water rush."

Collecting the water, or at least showing it can be collected, is where the Pittsburgh-based Astrobotic Technology comes in. The small company signed on in April for the third phase of a Small Business Innovative Research deal that continues research work to develop technologies NASA may need to harvest space resources in the future.

The company already is far along in its development of a rover that will work on its own. There is a deal in place with SpaceX to launch a lander and rover on a Falcon 9 rocket in October 2015. Astrobotic is competing against several other companies for the Google Lunar X-Prize, an award worth up to $30 million funded by the Internet search engine company.

"Our intent is to land on the surface of the moon in October 2015 and find water," said John Thornton, president of Astrobotic.

Water already on asteroids, the moon or Martian moons represent a potential bonanza to NASA's exploration plans because the resource can be put to use in so many critical ways for astronauts venturing into deep space. Water, made of hydrogen and oxygen molecules, can be turned into everything from breathing air to rocket fuel, not to mention the chance to filter it clean and drink it.

"Using these resources is the key to making space travel and habitation affordable and sustainable -- we are starting to learn how to live on another planetary surface," said Rob Mueller, a senior technologist in Kennedy's Surface Systems Office.

"It's a really interesting resource when you start to think about how to explore beyond Earth and to use the resources that are already in our solar system," Thornton said. "This is the first step toward harnessing the resources in the solar system for exploration and sustained presence beyond Earth."

Not having to launch those resources from Earth would dramatically cut the price tag for exploration, plus lower the risks involved for the crews as they venture into deep space on missions to an asteroid or Mars.

"There have been studies that have shown you can reduce the mass of a mission to Mars by a factor of somewhere between three and five if you get propellants from the space environment rather than launching them all from Earth," Metzger said.

Thornton said the fact that a number of companies are developing plans and building machines to go to the moon shows that the potential is real.

"If we were doing something really big and no one else was trying to do it, then it might not be that big," Thornton said.

Apollo astronauts found no signs of water ice as they walked on the surface of the moon near the equator from 1969 to 1972, nor did the soil and rock samples they brought back to Earth. However, several probes within the last 15 years found one indication after another that frozen water not only exists on the moon, but is abundant.

"None of these have been ground-proofed yet," Metzger said. "We really need to get vehicles on the surface of the moon prospecting to characterize those deposits, like how do they vary spatially, how do they vary with depth?"

A big question now is whether water ice on the moon is a powder akin to what skiers experience on a mountainside or is it completely solid like an ice cube, or did water seep down between granules of soil and freeze to produce rocks as hard as granite. It wouldn't surprise lunar researchers to find cases of all three as robotic prospectors explore the surface.

"Our best guess is it's going to be the ice," Thornton said. "Probably small little pieces of ice mixed in with the regolith."

Of course, there's more to exploration than knowing what questions to ask. There's also the issue of inventing technology that allows a robotic landing cheaply enough that a private company can pay for it, developing a rover heavy enough to drill or dig into the moon's surface without lifting itself off the ground in the low gravity, not to mention the matter of keeping the rover warm and powered in areas of the moon that are shadowed and surviving the lunar night.

Metzger has been pleased with what he has seen from the company so far.

"They're doing excellent work, they're excavator is progressing well," Metzger said.

Thornton said exchanging a modular digging element on the rover for a drill and instruments was not particularly difficult, and is an option for prospecting on the moon.

"The excavation chassis is a perfect fit for a mission to the moon in terms of scale, mass and power. We took out the excavation part and dropped in a drill and instruments," Thornton said.

Astrobotic will test its rover and tools in the bin of simulated lunar soil that Kennedy uses for its annual Lunabotics Mining competition to prove the vehicle is up to the challenges of operating on the moon.

"You have to be able to go to the moon with some confidence that your vehicle's going to be able to get around and to dig in the soil," Thornton said.

While NASA is excited about the chances to use a new resource for deep space exploration, Astrobotic wants to use the robotic prospector to start mapping where the biggest water deposits are, along with other helpful chemicals, and then use the information to develop ways to extract the materials from the moon and put it to use. There are no plans to return water or other lunar samples to the Earth, Thornton said.

"The beauty of sending a robot is they don't demand a return ticket," Thornton said. "Once we know where the water is and what form it is in, we can develop systems to produce it in useable quantities. Water is a critical resource because you can drink it, breathe it and use it for rocket fuel."

There are a great many questions to answer before astronauts can count on the moon, an asteroid or Martian moons as fuel and air depots, but Metzger and Thornton said the answers are within reach.

"That's the reason to go, because we don't know the answer," Thornton said.

Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by NASA.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here