Robots are exploring Mars

An army of robots currently is orbiting and crawling over Mars, including Spirit and Opportunity, the two successful rovers that refuse to die more than three years after their arrival. But Phoenix will do something they can't: Dig for ice. "And we're reasonably confident we will be able to sample the ice, which no previous mission has been able to do," says Carol Stoker, a Phoenix team member and planetary scientist with the National Aeronautics and Space Administration.