Semeykin Crater

This is an image within Semeykin Crater, which is located in the Martian northern hemisphere. This location is at the edge of the planetary dichotomy, a boundary between the heavily cratered and older southern highlands and the lightly cratered northern lowlands. This boundary is marked by remnants, or 'islands', of highland terrain standing out within the northern lowlands. It is uncertain how this dichotomy formed, but the interior of this crater has been resurfaced with the smoother, younger terrain. Much of the older remnants appear softened and in some areas channel-like features occur. This may be due to past or present subsurface ice that can deform the terrain and/or melt. Dark sand and dunes are visible on the right hand side of the image.