NASA’S Mars Rovers Head for New Sites After Studying Layers of Terrain AScribe

NASA’s Mars rover Spirit has reached a safe site for the Martian winter, while its twin, Opportunity, is making fast progress toward a destination of its own. The two rovers recently set out on important — but very different — drives after earlier weeks inspecting sites with layers of Mars history. Opportunity finished examining sedimentary evidence of ancient water at a crater called “Erebus,” and is now rapidly crossing flat ground toward the scientific lure of a much larger crater, “Victoria.”