Geological Chronicle
Positioned near the Moon's southeastern limb, Hamilton spans 57.45 kilometers in diameter along the uneven terrain of Mare Australe. Because of its peripheral location, Earth-based observers view the crater nearly edge-on, a perspective that limits visual detail and makes sightings dependent on lunar libration. The lava-flooded crater Oken lies almost due west, while the flooded crater Gum sits to the northeast and the flooded walled plain Lyot rests less than three crater diameters to the south.
The crater has not been noticeably degraded through impact erosion, retaining a well-formed edge and a nearly circular outline despite a somewhat straightened northern rim. Terraces line its interior sides, particularly along the western edge, which remains hidden from Earth view. Its floor is deep and uneven, marked by an impact feature joining the midpoint to the north-northwestern inner wall, and it lies concentric with an arc representing the surviving eastern rim of an older crater.
The crater is named for Sir William Rowan Hamilton, the Irish mathematician recognized as the inventor of quaternion theory.