Video: NASA's Mars Rover Opportunity Has Run a Marathon on Mars

Opportunity in Shadows
NASA's Mars Rover Opportunity catches its own late-afternoon shadow in this dramatically lit view eastward across Endeavour Crater on Mars.NASA/JPL/Cornell

All eyes will be on the new Mars rover Curiosity when it lands in just over two weeks, but lest we forget, NASA's indefatigable Mars rover Opportunity is still rolling along, too. The rover has driven about 22 miles, which prompted some Olympic-minded NASA people to realize the rover is nearing marathon distance. It will be the first interplanetary marathon.

This is made all the more impressive by the fact that Opportunity and its late twin, Spirit, were designed to drive about one-third of a mile in total. And the fact that Opportunity drives about 160 to 330 feet a day. Granted, it flew a long way to even get to the starting line: "This particular marathoner had to fly about 283 million miles across space before being unceremoniously drop-bounced on the Martian surface," said Ray Arvidson, the mission's deputy principal investigator, told NASA Science News.

Its main mission has been to look for water, and both rovers have found slam-dunk evidence that the Red Planet used to be a wet planet. Opportunity first found evidence of water at a site called Eagle Crater, and then spent the next few years driving around deeper and larger craters nearby. Since August of last year, it's been exploring Endeavour Crater, after traversing tricky Martian terrain "with no aid stations anywhere," as NASA Science cheekily puts it. It even had to drive backwards for a while after a wheel injury.

At Endeavour, Opportunity found some of its best evidence yet, including fractured rock filled with gypsum. Gypsum forms in the presence of water, and likely in more pH-neutral (and life-hospitable) conditions. Just a few weeks ago, the rover awoke from a winter slumber and left its winter resting place, Greeley Haven, to do some more exploring. There's still plenty of work to do, so a 26.2 mile total is certainly within the realm of possibility. Learn more about Opportunity's journey in this video.

Opportunity's Journey
This map plots the Mars rover Opportunity's journey across the Martian surface from its landing Jan. 25, 2004, through July 11, 2012. As of July 3, she had driven 21.43 miles.NASA/JPL