NASA’s Mars Exploration Rover Opportunity used its navigation camera to take this picture showing a light-toned rock, nicknamed Tisdale 2, on its 2 690th Martian day, or sol, of the rover’s work on Mars (18 August 2011). The rock is about 30cm tall.
In subsequent sols, the rover used tools on its robotic arm to examine Tisdale 2. That rock and others on the ground beyond it were apparently ejected by the impact that excavated a 20m-wide) crater, called Odyssey, which is nearby and to the left of this scene. Odyssey and these rocks are on a low ridge called Cape York, which is a segment of the western rim of Endeavour crater. Part of Opportunity’s array of photovoltaic cells is visible in the foreground. (Image: NASA/JPL-Caltech)