LOS ANGELES, Dec 4, 2012 (AP) — 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-colored 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 present.”
Squyres provided the update at a gathering of the American Geophysical Union in San Francisco.
Clays are important because they hold clues about the past Martian climate. They form in watery environments that are not too acidic and not too alkaline — in other words, conditions that might have been more suitable for microbes.