Orbiter Mars' moon Deimos from 500 km Viking 2 Orbiter image of Mars satellite Deimos from a distance of 500 km. Deimos is about 10 km across and north is up. At this distance the surface appears smooth. Many craters are partly hidden by regolith - soil and broken up material.
Closer views reveal a heavily cratered surface.
Deimos is irregularly shaped and extends about 10 km in its longest dimension.