NASA's Mars Exploration Rover Opportunity Keeps on Moving

From NASA:

A drive on Feb. 8, 2015, put NASA's Mars Exploration Rover Opportunity within 220 yards (200 meters) of having travelled the equivalent of a marathon distance of 26.219 miles (42.195 kilometers).

Opportunity is headed for a portion of the western rim of Endeavour Crater where observations by NASA's Mars Reconnaissance Orbiter have detected multiple types of clay minerals. These minerals are indicative of an ancient wet environment where water was more neutral rather than harshly acidic. More than six months ago, the rover team informally named that destination "Marathon Valley," having estimated what the odometry would total by the time Opportunity gets there.