The low ridge that appears as a dark band below the horizon in the center of this scene is a Martian outcrop called "Cooperstown," a possible site for contact inspection with tools on the robotic arm of NASA's Mars rover Curiosity. The ridge extends roughly 100 feet (about 30 meters) from left to right, and it is about 260 feet (about 80 meters) away from the location from which Curiosity captured this view.
The image combines portions of two frames taken by the Navigation Camera (Navcam) on Curiosity on the 437th Martian day, or sol, of the rover's mission inside Gale Crater on Mars (October 28, 2013).
Curiosity had just completed the mission's first use of two-sol autonomous driving. It resumed autonomous driving on Sol 437 where it had left off driving on Sol 436 (October 27, 2013). In autonomous driving, the rover itself chooses the best route to reach designated waypoints, using onboard analysis of stereo images that it takes during pauses in the drive. The combined two-sol drive that brought Curiosity to this vantage point, for seeing Cooperstown, covered about 410 feet (125 meters).
The left edge of the scene is toward south-southwest, with an edge of Mount Sharp on the horizon; the right edge is toward the west, with part of the rim of Gale Crater on the horizon.
Photo credit: NASA/JPL-Caltech
Note: For more information, see NASA's Curiosity Mars Rover Approaches 'Cooperstown'.