National Aeronautics and Space Administration scientists say that to reach the crater, named Endeavour, the rover will have to travel approximately 7 miles to the southeast, matching the total distance it has traveled since landing on Mars early in 2004. The rover climbed out of Victoria Crater earlier this month.

The Endeavour crater is 13.7 miles across. Opportunity will have to travel about 110 yards each day as it's driven toward the Endeavour crater. Even at that pace, scientists said the journey could take two years.

"This is a bolder, more aggressive objective than we have had before," said John Callas, project manager for both Mars rovers at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It's tremendously exciting. It's new science. It's the next great challenge for these robotic explorers."