NASA's Opportunity rover begins 10th year of science work on Mars As NASA's Mars Exploration Rover Opportunity neared the ninth anniversary of its landing on Mars, the rover was working in the 'Matijevic Hill' area seen in this view from Opportunity's panoramic camera. Credit: NASA/JPL-Caltech/Arizona State Univ. PASADENA, Calif., Jan. 23 (UPI) -- NASA says its rover Opportunity has begun its 10th year of "exploration and scientific discovery" on Mars by examining rocks on the rim of an ancient crater. Opportunity has been operating on the Red Plant 36 times longer than the three months originally planned as its prime mission, NASA's Jet Propulsion Laboratory in Pasadena, Calif., reported Tuesday. Since it landed on Mars in January 2004, Opportunity has driven 22.03 miles, considerable more than the drive of about 2,000 feet intended in its original mission plan. Tasked with investigating whether its local landing environment had ever been wet, it transmitted evidence in its first three months that water long ago soaked the ground and flowed across the surface. The mission team at JPL has since then guided Opportunity across the plains of the Meridiani Planum region to successively larger craters for access to material naturally exposed from deeper, older layers of Martian history. "What's most important is not how long it has lasted or even how far it has driven, but how much exploration and scientific discovery Opportunity has accomplished," JPL's John Callas, manager of NASA's Mars Exploration Rover Project, said. The project has included both Opportunity and its twin rover, Spirit, which stopped functioning in 2010.