It's amazing how much excitement a rock on Mars can generate, especially a rock that recently "appeared" in front of NASA's Mars Exploration Rover (MER) Opportunity. But despite its mysterious arrival in front of the rover's panoramic camera, mission scientists have a pretty good idea where it came from. And now we can see the rock star in full ruddy color.
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The "jelly doughnut-sized" rock, dubbed "Pinnacle Island", was announced at a special NASA Jet Propulsion Laboratory "10 years of roving Mars" event at the California Institute of Technology (Caltech), Pasadena, Calif., on Jan. 16. As discussed by Cornell University's Steve Squyres, principal investigator of the MER program, the rock either originated from a) the rover ‘flipping' a loose rock from beneath its wheel, or b) it was ejecta from a nearby meteorite impact. Although the latter would be most exciting, Squyres pointed to the "rock flipping" event as being the most likely source.
This may sound mundane - after all, wouldn't it be awesome if Opportunity was near "ground zero" of a small impact event! - but Squyres and his team are thrilled about the incredible science Pinnacle Island could provide the veteran Mars rover.
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"(The rock) obligingly turned upside down, so we're seeing a side that hasn't seen the Martian atmosphere in billions of years and there it is for us to investigate. It's just a stroke of luck," Squyres told Discovery News.
In a JPL news release, color versions of the "before" and "after" shots of the ground in front of Opportunity have been released. These new images provide a new perspective on the nature of the rock.
"Much of the rock is bright-toned, nearly white," writes the release. "A portion is deep red in color. Pinnacle Island may have been flipped upside down when a wheel dislodged it, providing an unusual circumstance for examining the underside of a Martian rock."
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Already the rover has been getting up-close and personal with its serendipitous science target, using its robotic arm-mounted Microscopic Imager to analyze the bright underbelly of the rock. It will be interesting to see what the rover learns from Pinnacle Island.
Opportunity is currently located on a north-facing slope of the rim of Endeavor Crater called "Murray Ridge" during its sixth Martian winter. It has been exploring the edge of the crater since 2011. The six-wheeled robot, which arrived on the Martian surface with sister rover Spirit in January 2004, has notched up nearly 23 miles of Mars roving so far. The mission's primary mission was only 3 months. Spirit has since succumbed to the Martian elements, getting stuck in a sand trap inside Gusev Crater in 2009. Spirit was declared lost in March 2010.