2. Rampart Ejecta

Most fresh impact craters on Mars display rounded, lobate ejecta blankets commonly referred to as rampart ejecta. This type of ejecta may result from the fluidization of subsurface ice heated by the impact process. If so, the global distribution of rampart craters suggests that vast stores of subsurface water and ice exist on the planet. Note the occurrence of central peaks in some of the larger craters. Central peaks are common in impact craters greater than about 10-km in diameter on Mars.

Central peak crater near center of image is 13 km in diameter and located at 34.3° N, 258.6° W; Viking Orbiter frame 538A03

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