September 3, 2015: Opportunity Digs Marathon Valley Walkabout: Opportunity drove farther into Marathon Valley in August, dug into what appears to be a water-altered rock, and took a lot of picture postcards in what is turning out to be a distinctively different site from any that the Mars Exploration Rovers mission has found since the robot field geologist landed in 2004.
“It’s a place that’s unique relative to where we’ve been before,” said Ray Arvidson, MER deputy principal investigator, of Washington University St. Louis. “This is virgin territory for us.” [...]
Opportunity entered the Marathon Valley last month and is in the midst of a geological walkabout to see what’s there. “The objective is to cover the whole territory pretty comprehensively before winter sets in later this year,” said Steve Squyres, MER principal investigator, of Cornell University. But Marathon Valley is a lot bigger than Matijevic Hill, where the mission made history in 2013 ground-truthing the first clay minerals found by a surface mission on Mars. “So this walkabout will take time,” he said. [More at link]