The solar-powered Opportunity has been exploring the rim of a huge crater since August. With winter approaching, the six-wheel rover is on the lookout for a place with good sunlight.
Opportunity and its twin, Spirit, parachuted to opposite ends of the red planet in January 2004. Earlier this year, NASA declared Spirit's mission over after it repeatedly failed to contact Earth.
Opportunity won't be alone on the Martian surface for long. NASA last month launched a mega-rover named Curiosity that is set to land next summer.
Mars mission: http://marsrover.nasa.gov/home/index.html