NASA's Mars Exploration Rover Spirit drove 6.98 meters (22.9 feet) southeastward on the 1,871st Martian day, or sol, of the rover's mission on Mars (April 8, 2009). As usual since losing the use of its right-front wheel in 2006, Spirit drove backward, dragging the immobile wheel. Image credit: NASA/JPL-Caltech. Full image and caption | Universe Today