The First Martian Marathon   
       
   May 15, 2015:  On Earth, the fastest runners can finish a marathon in hours.    
   On Mars it takes about 11 years.   
       
   On Tuesday, March 24th 2015, NASA's Mars rover Opportunity completed its first   
   Red Planet marathon-- 26.219 miles - with a finish time of roughly 11 years   
   and two months.   
       
   https://www.youtube.com/watch?v=9gN_cmK9TUc&feature=youtu.be   
       
   A new ScienceCast video follows Opportunity on its marathon trek across Mars.    
   Play it   
       
   "This mission isn't about setting distance records; it's about making   
   scientific discoveries," says Steve Squyres, Opportunity principal   
   investigator at Cornell University. "Still, running a marathon on Mars feels   
   pretty cool."   
       
   Runner-author Hal Higdon once said, "The marathon never ceases to be a race of   
   joy, a race of wonder." That goes double for a marathon on another world where   
   every mile promises a new discovery.   
       
   Opportunity's mission is to search for signs of ancient water. Today the Red   
   Planet has a breathtakingly thin atmosphere, with conditions deadly to almost   
   every known form of life on Earth. Billions of years ago, however, things   
   might have been different. Many researchers believe that Mars was once warmer,   
   wetter, and friendlier to potential Martian life. Opportunity's job is to   
   search for clues to that ancient time.   
       
   Like many long-distance runners, Opportunity likes to "take it slow." On a   
   typical drive day, the rover travels only 50 to 100 meters.  This gives the   
   rover time to safely traverse the rocky terrain, pause and look for the   
   unknown. True to form, the long-lived rover surpassed the marathon mark during   
   a drive of only 46.9 meters or 154 feet.   
       
   http://mars.nasa.gov/mer/home/   
       
   Visit NASA's Mars Exploration Rover home page"When Opportunity landed on Mars   
   11 years ago, no one imagined this vehicle surviving a Martian winter, let   
   alone completing a marathon," said Mars Exploration Rover Project Manager John   
   Callas of JPL. To celebrate, the Mars rover team at JPL held a marathon-length   
   relay race.   
       
   For Opportunity, just getting to the starting line was epic: "This particular   
   marathoner had to fly about 283 million miles across space before being   
   unceremoniously drop-bounced on the Martian surface in 2004," recalls Ray   
   Arvidson, a member of the Opportunity science team from Washington University.   
       
   Opportunity first uncovered signs of water in deposits near the landing site   
   in Eagle Crater.  There were rocks that seemed to have formed in an ancient   
   shallow lake, albeit too acidic for life.  Next, mission planners set their   
   sights on Endeavour Crater - an enormous pit 14 miles wide and hundreds of   
   meters deep. Endeavour's depth would offer a look farther back into the   
   history of Mars, to a time when the water was possibly less acidic.   
       
   The marathon route crossing Mars' Meridiani plain to Endeavour was a daring   
   trek -with no aid stations anywhere. Raging dust storms reduced the rover's   
   solar power so much that Opportunity almost entered the "sleep of death";   
   soft, sandy, wind-blown ripples trapped the rover's wheels, and there was an   
   injury: a failure in Opportunity's right front steering actuator, which made   
   running forward tricky. Ever resourceful, the rover ran part of its race   
   backwards.   
       
   When the marathoner reached Endeavour Crater in August 2011, things got   
   interesting.   
       
   "Endeavour is surrounded by fractured sedimentary rock, and the cracks are   
   filled with gypsum," says Arvidson. "Gypsum forms when groundwater comes up   
   and fills cracks in the ground, so this was good evidence for liquid water."   
       
   Moreover, the gypsum veins were likely formed in conditions less acidic and   
   possibly more hospitable to life: Jackpot!   
       
   What's next? Opportunity is still going strong as it heads for a gap in the   
   rim of Endeavour Crater where the rover will explore clay deposits for more   
   signs of ancient water. The gap is called-you guessed it-"Marathon Valley."   
       
   Martian ultra-marathon, anyone?   
       
   Credits:   
   Author: Dr. Tony Phillips | Production editor: Dr. Tony Phillips | Credit:   
   Science@NASA   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.99   
    * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)