Hello All!   
      
   Curiosity Finds Old Streambed on Mars   
      
   Sept. 27, 2012: NASA's Curiosity rover mission has found evidence a stream   
   once ran vigorously across the area on Mars where the rover is driving. There   
   is earlier evidence for the presence of water on Mars, but this evidence --   
   images of rocks containing ancient streambed gravels -- is the first of its   
   kind.    
      
   "From the size of gravels it carried, we can interpret the water was moving   
   about 3 feet per second, with a depth somewhere between ankle and hip deep,"   
   said Curiosity science co-investigator William Dietrich of the University of   
   California, Berkeley. "Plenty of papers have been written about channels on   
   Mars with many different hypotheses about the flows in them. This is the first   
   time we're actually seeing water-transported gravel on Mars. This is a   
   transition from speculation about the size of streambed material to direct   
   observation of it."    
      
   http://www.youtube.com/watch?v=7sT6FOIfVOI   
      
   NASA's Curiosity rover found evidence for an ancient, flowing stream on Mars   
   at a few sites, including the rock outcrop pictured here, which the science   
   team has named "Hottah" after Hottah Lake in Canada's Northwest Territories.   
   Image credit: NASA/JPL-Caltech/MSSS    
      
   The finding site lies between the north rim of Gale Crater and the base of   
   Mount Sharp, a mountain inside the crater. Earlier imaging of the region from   
   Mars orbit allows for additional interpretation of the gravel-bearing   
   conglomerate. The imagery shows an alluvial fan of material washed down from   
   the rim, streaked by many apparent channels, sitting uphill of the new finds.    
      
   The rounded shape of some stones in the conglomerate indicates long-distance   
   transport from above the rim, where a channel named Peace Vallis feeds into   
   the alluvial fan. The abundance of channels in the fan between the rim and   
   conglomerate suggests flows continued or repeated over a long time, not just   
   once or for a few years.    
      
   The discovery comes from examining two outcrops, called "Hottah" and "Link,"   
   with the telephoto capability of Curiosity's mast camera during the first 40   
   days after landing. Those observations followed up on earlier hints from   
   another outcrop, which was exposed by thruster exhaust as Curiosity, the Mars   
   Science Laboratory Project's rover, touched down.    
      
   "Hottah looks like someone jack-hammered up a slab of city sidewalk, but it's   
   really a tilted block of an ancient streambed," said Mars Science Laboratory   
   Project Scientist John Grotzinger of the California Institute of Technology in   
   Pasadena.    
      
   The gravels in conglomerates at both outcrops range in size from a grain of   
   sand to a golf ball. Some are angular, but many are rounded.    
      
   "The shapes tell you they were transported and the sizes tell you they   
   couldn't be transported by wind. They were transported by water flow," said   
   Curiosity science co-investigator Rebecca Williams of the Planetary Science   
   Institute in Tucson, Ariz.    
      
   The science team may use Curiosity to learn the elemental composition of the   
   material, which holds the conglomerate together, revealing more    
   haracteristics of the wet environment that formed these deposits. The stones   
   in the conglomerate provide a sampling from above the crater rim, so the team   
   may also examine several of them to learn about broader regional geology.    
      
   The slope of Mount Sharp in Gale Crater remains the rover's main destination.   
   Clay and sulfate minerals detected there from orbit can be good preservers of   
   carbon-based organic chemicals that are potential ingredients for life.    
      
   "A long-flowing stream can be a habitable environment," said Grotzinger. "It   
   is not our top choice as an environment for preservation of organics, though.   
   We're still going to Mount Sharp, but this is insurance that we have already   
   found our first potentially habitable environment."    
      
      
   Production editor: Dr. Tony Phillips | Credit: Science@NASA   
      
   More Information    
   During the two-year prime mission of the Mars Science Laboratory, researchers   
   will use Curiosity's 10 instruments to investigate whether areas in Gale   
   Crater have ever offered environmental conditions favorable for microbial   
   life.    
      
   NASA's Jet Propulsion Laboratory, a division of Caltech, built Curiosity and   
   manages the Mars Science Laboratory Project for NASA's Science Mission   
   Directorate, Washington.    
      
   For more about Curiosity, visit: http://www.nasa.gov/msl and htt   
   ://mars.jpl.nasa.gov/msl .    
      
   You can follow the mission on Facebook and Twitter at: http://ww   
   .facebook.com/marscuriosity and http://www.twitter.com/marscuriosity .    
       
      
   Regards,   
      
   Roger    
   --- timEd/386 1.10.y2k+   
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