Rover Opportunity may be at clay-rich site on Mars This image
provided by NASA shows a shadow self-portrait taken by NASA’s
Opportunity rover on the Martian surface. The solar-powered
spacecraft has been exploring a huge crater in the Martian
southern hemisphere and has detected what appear to be clay
minerals. (AP Photo NASA Published Wednesday, December 5, 2012
9:30AM EST LOS ANGELES -- After rolling around the Martian
plains for more than eight years, the Opportunity rover finally
found a spot believed to be rich in clay minerals, scientists
said Tuesday. Orbiting spacecraft previously detected the
presence of clay-bearing deposits at a huge crater in Mars'
southern hemisphere. Using that information as a guide, the six-
wheel, solar-powered rover drove around the rim and encountered
light-coloured rocks never before seen in past explorations.
"This is the sweet spot," said mission chief scientist Steve
Squyres of Cornell University. "This is the place where the
orbital data tells us that the clays are pres