Those "never say die" robots on Mars-- NASA's Spirit and Opportunity--continue to chalk up science at their respective exploration sites. Looming large for the Opportunity rover at Meridiani Planum is Victoria Crater--a grand bit of territory that's roughly half a mile (800 meters) in diameter. That's about six times wider than Endurance Crater, a feature that the rover previously surveyed for several months in 2004, gathering data on rock layers there that were affected by water of long, long ago. "We are closing in ... we've got only about a kilometer to go now," said Steve Squyres, lead scientist at...