Showing posts with label water on moon. Show all posts
Showing posts with label water on moon. Show all posts
Friday, May 27, 2011
Saturday, October 30, 2010
NASA Trapped Mars Rover Finds Evidence of Subsurface Water
PASADENA, Calif. -- The ground where NASA's Mars Exploration Rover Spirit became stuck last year holds evidence that water, perhaps as snow melt, trickled into the subsurface fairly recently and on a continuing basis.
Stratified soil layers with different compositions close to the surface led the rover science team to propose that thin films of water may have entered the ground from frost or snow. The seepage could have happened during cyclical climate changes in periods when Mars tilted farther on its axis. The water may have moved down into the sand, carrying soluble minerals deeper than less soluble ones. Spin-axis tilt varies over timescales of hundreds of thousands of years.
The relatively insoluble minerals near the surface include what is thought to be hematite, silica and gypsum. Ferric sulfates, which are more soluble, appear to have been dissolved and carried down by water. None of these minerals are exposed at the surface, which is covered by wind-blown sand and dust.
"The lack of exposures at the surface indicates the preferential dissolution of ferric sulfates must be a relatively recent and ongoing process since wind has been systematically stripping soil and altering landscapes in the region Spirit has been examining," said Ray Arvidson of Washington University in St. Louis, deputy principal investigator for the twin rovers Spirit and Opportunity.
Analysis of these findings appears in a report in the Journal of Geophysical Research published by Arvidson and 36 co-authors about Spirit's operations from late 2007 until just before the rover stopped communicating in March.
The twin Mars rovers finished their three-month prime missions in April 2004, then kept exploring in bonus missions. One of Spirit's six wheels quit working in 2006.
In April 2009, Spirit's left wheels broke through a crust at a site called "Troy" and churned into soft sand. A second wheel stopped working seven months later. Spirit could not obtain a position slanting its solar panels toward the sun for the winter, as it had for previous winters. Engineers anticipated it would enter a low-power, silent hibernation mode, and the rover stopped communicating March 22. Spring begins next month at Spirit's site, and NASA is using the Deep Space Network and the Mars Odyssey orbiter to listen if the rover reawakens.
Researchers took advantage of Spirit's months at Troy last year to examine in great detail soil layers the wheels had exposed, and also neighboring surfaces. Spirit made 13 inches of progress in its last 10 backward drives before energy levels fell too low for further driving in February. Those drives exposed a new area of soil for possible examination if Spirit does awaken and its robotic arm is still usable.
"With insufficient solar energy during the winter, Spirit goes into a deep-sleep hibernation mode where all rover systems are turned off, including the radio and survival heaters," said John Callas, project manager for Spirit and Opportunity at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "All available solar array energy goes into charging the batteries and keeping the mission clock running."
The rover is expected to have experienced temperatures colder than it has ever before, and it may not survive. If Spirit does get back to work, the top priority is a multi-month study that can be done without driving the rover. The study would measure the rotation of Mars through the Doppler signature of the stationary rover's radio signal with enough precision to gain new information about the planet's core. The rover Opportunity has been making steady progress toward a large crater, Endeavour, which is now approximately 8 kilometers (5 miles) away.
Spirit, Opportunity, and other NASA Mars missions have found evidence of wet Martian environments billions of years ago that were possibly favorable for life. The Phoenix Mars Lander in 2008 and observations by orbiters since 2002 have identified buried layers of water ice at high and middle latitudes and frozen water in polar ice caps. These newest Spirit findings contribute to an accumulating set of clues that Mars may still have small amounts of liquid water at some periods during ongoing climate cycles.
JPL, a division of the California Institute of Technology in Pasadena, manages the rovers for the agency's Science Mission Directorate in Washington.
More information about the rovers is online at: http://www.nasa.gov/rovers .
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Saturday, October 23, 2010
NASA: Lunar Impact Uncovered More Than Just Moon Water
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| NASA Illustration |
NASA
Nearly a year after announcing the discovery of water molecules on the moon, scientists have revealed new data uncovered by NASA's Lunar CRater Observation and Sensing Satellite, or LCROSS, and Lunar Reconnaissance Orbiter, or LRO—and it's more than just water.
The missions found evidence that lunar soil within shadowy craters is rich in useful materials. Moreover, the moon appears to be chemically active and has a full-fledged water cycle. Scientists also confirmed that 'moon water' was in the form of mostly pure ice crystals in some places.
These results are featured in six papers published in the Oct. 22 issue of Science.
The twin impacts of LCROSS and a companion rocket stage in the moon's Cabeus crater on Oct. 9, 2009, lifted a plume of material that might not have seen direct sunlight for billions of years. As the plume traveled nearly 10 miles above the crater’s rim, instruments aboard LCROSS and LRO made observations of the crater and debris and vapor clouds. After the impacts, grains of mostly pure water ice were lofted into the sunlight in the vacuum of space.
"Seeing mostly pure water ice grains in the plume means water ice was somehow delivered to the moon in the past, or chemical processes have been causing ice to accumulate in large quantities," said Anthony Colaprete, LCROSS project scientist and principal investigator at NASA's Ames Research Center.
In addition to water, the plume contained "volatiles." These are compounds that freeze in the cold lunar craters and vaporize easily when warmed by the sun. The suite of LCROSS and LRO instruments determined as much as 20 percent of the material kicked up by the LCROSS impact was volatiles, including methane, ammonia, hydrogen gas, carbon dioxide and carbon monoxide.
"The diversity and abundance of volatiles in the plume suggest a variety of sources, like comets and asteroids, and an active water cycle within the lunar shadows," says Colaprete.
The instruments also discovered relatively large amounts of light metals such as sodium, mercury and possibly even silver. Scientists believe the water and mix of volatiles that LCROSS and LRO detected could be the remnants of a comet impact. According to scientists, these volatile chemical by-products are also evidence of a cycle through which water ice reacts with lunar soil grains.
LRO's Diviner instrument gathered data on water concentration and temperature measurements, and LRO's Lunar Exploration Neutron Detector mapped the distribution of hydrogen. This combined data led the science team to conclude the water is not uniformly distributed within the shadowed cold traps, but rather is in pockets, which may also lie outside the shadowed regions.
The proportion of volatiles to water in the lunar soil indicates a process called "cold grain chemistry" is taking place. Scientists also theorize this process could take as long as hundreds of thousands of years and may occur on other frigid, airless bodies such as asteroids; the moons of Jupiter and Saturn (including Europa and Enceladus); Mars' moons; interstellar dust grains floating around other stars and the polar regions of Mercury.
"The observations by the suite of LRO and LCROSS instruments demonstrate the moon has a complex environment that experiences intriguing chemical processes," said Richard Vondrak, LRO project scientist at NASA's Goddard Space Flight Center. "This knowledge can open doors to new areas of research and exploration."
By understanding the processes and environments that determine where water ice will be, how water was delivered to the moon and its active water cycle, future mission planners might be better able to determine which locations will have easily-accessible water. The existence of mostly pure water ice could mean future human explorers won't have to devise complicated processes to retrieve water out of the soil in order to use it for valuable life support resources. In addition, an abundant presence of hydrogen gas, ammonia and methane could be exploited to produce fuel.
"NASA has convincingly confirmed the presence of water ice and characterized its patchy distribution in permanently shadowed regions of the moon," concludes Michael Wargo, chief lunar scientist at NASA Headquarters in Washington. "This major undertaking is the one of many steps NASA has taken to better understand our solar system, its resources, and its origin, evolution, and future."
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Friday, October 22, 2010
NASA Moon Bombing Turns Up Twice as Much Water as Initially Measured
Associated Press
LOS ANGELES — When NASA blasted a hole in the moon last year in search of water, scientists figured there would be a splash. They just didn't know how big. Now new results from the Hollywood-esque moonshot reveal lots of water in a crater where the sun never shines – 41 gallons of ice and vapor.
That may not sound like much – it's what a typical washing machine uses for a load – but it's almost twice as much as researchers had initially measured and more than they ever expected to find.
The estimate represents only what scientists can see from the debris plume that was kicked up from the high-speed crash near the south pole by a NASA spacecraft on Oct. 9, 2009.
Mission chief scientist Anthony Colaprete of the NASA Ames Research Center calculates there could be 1 billion gallons of water in the crater that was hit – enough to fill 1,500 Olympic-sized swimming pools.
"Where we impacted was quite wet," Colaprete said, adding there could be more such craters at both the moon's poles.
Proof that the moon is dynamic and not a dry, desolate world offers hope for a possible future astronaut outpost where water on site could be used for drinking or making rocket fuel.
But the scientists' excitement is tempered by the political reality that there's no plan to land on the moon anytime soon.
The $79 million moon mission known as the Lunar Crater Observation and Sensing Satellite, or LCROSS, was launched to determine whether water exists at the moon's poles. Previous spacecraft spied hints of possible ice in polar craters.
The mission involved slamming a spent rocket into Cabeus crater. The crash carved a hole about one quarter the size of a football field.
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