Red Planet Report

August 3, 2015: Opportunity Enters Marathon Valley, Begins Walkabout: Nearly seven Earth years after the Mars Exploration Rovers mission set its sights on Endeavour Crater, Opportunity cruised into Marathon Valley, the once-but-a-dream destination where orbital data indicate there is a mother lode of bold signs of ancient past water.

“It’s great to be in Marathon Valley,” said Steve Squyres, MER principal investigator, of Cornell University. “It was a long haul. Based on the orbital data, the highest concentration of phyllosilicates we’ve ever seen with either rover is here. Just in terms of what we know about the place from orbit, it’s expected to be scientifically very productive.”

From high overhead, Marathon Valley looks like a notch in the Cape Tribulation segment of Endeavour Crater’s eroded western rim. It stretches generally west to east for some 330 meters (1100 feet), the length of three American football fields, into the big crater… [More at link]

Sol 4096, August 2, 2015. Opportunity is edging slowly down into Marathon Valley. Three Navcam frames show the valley’s north wall at left and in the distance, the floor of Endeavour Crater, with dunes, both static (light-color, center) and active (dark, at right). Click to enlarge.

Opportunity raw images, its latest mission status, a location map. and atmospheric opacity, known as tau.