Three months after being stopped in their tracks by a global dust storm on the Red Planet, NASA's twin Mars rovers have resumed operations. On Sept. 13, the rover Opportunity finally began a long-delayed descent into the 800-meter-wide Victoria crater. The golf cart–size vehicle is now studying a band of flat bedrock that lies just below the rim of the crater. The exposed bedrock, which in most places on Mars lies far below the surface, may hold clues to conditions on the planet millions of years ago.
Halfway around the planet, the rover Spirit is now examining the surface of a plateau dubbed Home Plate. Rocks there show signs of having been subjected to volcanic activity in the presence of water.
Researchers had worried that t