Hello All!   
      
   Mystery Spheres on Mars    
      
   Sept. 14, 2012:  NASA's long-lived rover Opportunity has returned an image of   
   the Martian surface that is puzzling researchers.    
      
   Spherical objects concentrated at an outcrop called Kirkwood on the western   
   rim of Endeavour Crater differ in several ways from iron-rich spherules   
   nicknamed "blueberries" the rover found at its landing site in early 2004.    
      
   "This is one of the most extraordinary pictures from the whole mission," said   
   Opportunity's principal investigator, Steve Squyres of Cornell University in   
   Ithaca, N.Y. "Kirkwood is chock full of a dense accumulation of these small   
   spherical objects. Of course, we immediately thought of the blueberries, but   
   this is something different. We never have seen such a dense accumulation of   
   spherules in a rock outcrop on Mars."    
      
   http://www.nasa.gov/mission_pages/mer/multimedia/pia16139.html   
      
   Using its Microscopic Imager, Opportunity photographed these small spherical   
   objects on Sept. 6, 2012. The view covers an area about 2.4 inches across at   
   an outcrop called "Kirkwood" on the western rim of Endeavour Crater. Larger   
   image   
      
   The spheres measure as much as one-eighth of an inch (3 millimeters) in   
   diameter. The analysis is still preliminary, but it indicates that these   
   spheres do not have the high iron content of Martian blueberries.    
      
   The Martian blueberries found elsewhere by Opportunity are concretions formed   
   by action of mineral-laden water inside rocks, evidence of a wet environment   
   on early Mars. Concretions result when minerals precipitate out of water to   
   become hard masses inside sedimentary rocks. Many of the Kirkwood spheres are   
   broken and eroded by the wind. Where wind has partially etched them away, a   
   concentric structure is evident.    
      
   Opportunity used the microscopic imager on its arm to look closely at   
   Kirkwood. Researchers checked the spheres' composition by using an instrument   
   called the Alpha Particle X-Ray Spectrometer on Opportunity's arm.    
      
   "They seem to be crunchy on the outside, and softer in the middle," Squyres   
   said. "They are different in concentration. They are different in structure.   
   They are different in composition. They are different in distribution. So, we   
   have a wonderful geological puzzle in front of us. We have multiple working   
   hypotheses, and we have no favorite hypothesis at this time. It's going to   
   take a while to work this out, so the thing to do now is keep an open mind and   
   let the rocks do the talking."    
      
   Just past Kirkwood lies another science target area for Opportunity. The   
   location is an extensive pale-toned outcrop in an area of Cape York where   
   observations from orbit have detected signs of clay minerals. That may be the   
   rover's next study site after Kirkwood. Four years ago, Opportunity departed   
   Victoria Crater, which it had investigated for two years, to reach different   
   types of geological evidence at the rim of the much larger Endeavour Crater.    
      
   The rover's energy levels are favorable for the investigations. Spring equinox   
   comes this month to Mars' southern hemisphere, so the amount of sunshine for   
   solar power will continue increasing for months.  Indeed, Opportunity is on   
   the verge of completing the first Martian Marathon.    
      
   "The rover is in very good health considering its 8-1/2 years of hard work on   
   the surface of Mars," said Mars Exploration Rover Project Manager John Callas   
   of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Energy production   
   levels are comparable to what they were a full Martian year ago, and we are   
   looking forward to productive spring and summer seasons of exploration."    
      
      
   Production editor: Dr. Tony Phillips | Credit: Science@NASA   
      
   More Information    
   Opportunity Runs the First Martian Marathon -- Science@NASA    
      
   NASA launched the Mars rovers Spirit and Opportunity in the summer of 2003,   
   and both completed their three-month prime missions in April 2004. They   
   continued bonus, extended missions for years. Spirit finished communicating   
   with Earth in March 2010. The rovers have made important discoveries about wet   
   environments on ancient Mars that may have been favorable for supporting   
   microbial life.    
      
   JPL manages the Mars Exploration Rover Project for NASA's Science Mission   
   Directorate in Washington.    
      
   To view the image of the area, visit: http://www.nasa.gov/missio   
   _pages/mer/multimedia/pia16139.html   
      
   For more information about Opportunity, visit: http://www.nasa.gov/rovers and   
   http://marsrovers.jpl.nasa.gov   
      
   You can follow the project on Twitter and on Facebook at: http:/   
   twitter.com/MarsRovers and http://www.facebook.com/mars.rovers .    
      
      
   Regards,   
      
   Roger    
   --- timEd/386 1.10.y2k+   
    * Origin: NCS BBS - Houma, LoUiSiAna - (1:3828/7)