Mars Rover Solves Doughnut Riddle   
       
   Feb. 14, 2014:  What if a rock that looked like a jelly doughnut suddenly   
   appeared on Mars? That's just what happened in front of Mars rover Opportunity   
   last month. Researchers have since determined that the "doughnut" is a piece   
   of a larger rock broken and moved by the rover's wheels in early January.   
       
   http://apod.nasa.gov/apod/ap140129.html   
       
   These two images from Mars rover Opportunity show a rock resembling a jelly   
   donut appearing in January 2014. More   
       
   Only about 1.5 inches wide (4 centimeters), the white-rimmed, red-centered   
   rock--now called "Pinnacle Island"--caused a stir last month when it appeared   
   in an image the rover took Jan. 8 at a location where it was not present four   
   days earlier. More recent images show the original piece of rock struck by the   
   rover's wheel, slightly uphill from where Pinnacle Island came to rest.   
       
   "Once we moved Opportunity a short distance, after inspecting Pinnacle Island,   
   we could see directly uphill an overturned rock that has the same unusual   
   appearance," said Opportunity Deputy Principal Investigator Ray Arvidson of   
   Washington University in St. Louis. "We drove over it. We can see the track.   
   That's where Pinnacle Island came from."   
       
   Examination of Pinnacle Island revealed high levels of elements such as   
   manganese and sulfur, suggesting these water-soluble ingredients were   
   concentrated in the rock by the action of water. "This may have happened just   
   beneath the surface relatively recently," Arvidson said, "or it may have   
   happened deeper below ground longer ago and then, by serendipity, erosion   
   stripped away material above it and made it accessible to our wheels."   
       
   Now that the rover is finished inspecting this rock, the team plans to drive   
   Opportunity south and uphill to investigate exposed rock layers on the slope.   
       
   http://tinyurl.com/k6ky6my   
       
   This image from Opportunity's panoramic camera (Pancam) shows where a rock   
   called "Pinnacle Island" had been before it appeared in front of the rover in   
   early January 2014.   
       
   Opportunity is approaching a boulder-studded ridge informally named the   
   McClure-Beverlin Escarpment, in honor of engineers Jack Beverlin and Bill   
   McClure. Beverlin and McClure were the first recipients of the NASA Medal of   
   Exceptional Bravery for their actions on Feb. 14, 1969 to save NASA's second   
   successful Mars mission, Mariner 6, when the launch vehicle began to crumple   
   on the launch pad from loss of pressure.   
       
   "Our team working on Opportunity's continuing mission of exploration and   
   discovery realizes how indebted we are to the work of people who made the   
   early missions to Mars possible, and in particular to the heroics of Bill   
   McClure and Jack Beverlin," said rover team member James Rice of the Planetary   
   Science Institute, Tucson, Ariz. "We felt this was really a fitting tribute to   
   these brave men, especially with the 45th anniversary of their actions coming   
   today."   
       
   Opportunity's work on the north-facing slope below the escarpment will give   
   the vehicle an energy advantage by tilting its solar panels toward the winter   
   sun. Feb. 14 is the winter solstice in Mars' southern hemisphere, where   
   Opportunity has been working since it landed in January 2004.   
       
   "We are now past the minimum solar-energy point of this Martian winter," said   
   Opportunity Project Manager John Callas of NASA's Jet Propulsion Laboratory   
   (JPL) in Pasadena, Calif.  "We now can expect to have more energy available   
   each week. What's more, recent winds removed some dust from the rover's solar   
   array. So we have higher performance from the array than the previous two   
   winters."   
       
   For more information about NASA's Mars rovers, visit nasa.gov/rovers   
       
   Credits:   
   Production editor: Dr. Tony Phillips | Credit: Science@NASA   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.98   
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