Mars - Mariner 9

Central caldera of Olympus Mons on Mars

Mars
Mariner 9 image of the central caldera of the Martian volcano, Olympus Mons. The basic morphology is similar to terrestrial calderas, although the scale is much larger. The smallest (and youngest) collapse pit, at right, is 30 km across. Concentric fractures and terrace are visible in the larger parts of the caldera. The caldera is about 29 km above the mean Martian surface. North is at 7:00. (Mariner 9, MTVS 4265-52)