Lunar Impact Uncovered More Than Just Moon Water   
       
   Oct. 21, 2010:  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.   
   [...]   
   An artist's concept of LCROSS approaching the moon in Oct. 2009. [more] 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.   
   [...]   
   Above: A surface temperature map of the lunar south pole made by LRO's Diviner   
   Lunar Radiometer Experiment . The map contains several intensely cold impact   
   craters that could trap water ice and other icy compounds commonly observed in   
   comets. The approximate maximum temperatures at which these compounds would be   
   frozen in place for more than a billion years are noted at right. [larger   
   image]   
       
   "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.   
   [...]   
   These experiments at the Ames Vertical Gun Range helped researchers understand   
   the LCROSS impact. Solid impacts send debris to the side (left), whereas   
   hollow impacts result in a high-angle ejecta plume (right). The primary LCROSS   
   impact was an emptied rocket and acted like a hollow projectile. Image credit:   
   Brown University/Peter H. Schultz and Brendan Hermalyn, NASA/Ames Vertical Gun   
   Range. [larger image]   
       
   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."   
   [...]   
   Click to view videos of the LCROSS/LRO results.   
       
   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."   
       
       
   Editor: Dr. Tony Phillips | Credit: Science@NASA   
       
   More Information   
   For more information about LCROSS and a complete list of the papers and their   
   authors, visit: http://www.nasa.gov/lcross   
       
   For more information about the LRO mission, visit: http://www.nasa.gov/lro   
       
   LCROSS launched with LRO aboard an Atlas V rocket from Cape Canaveral, Fla.,   
   on June 18, 2009, and used the Centaur upper stage rocket to create the debris   
   plume. The research was funded by NASA's Exploration Systems Missions   
   Directorate at the agency's headquarters. LCROSS was managed by Ames and built   
   by Northrop Grumman in Redondo Beach, Calif. LRO was built and is managed by   
   Goddard.   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.56   
    * Origin: NCS BBS (1:3828/7)