Fermat (Moon)

Named after Pierre De Fermat - French mathematician (1601-1665).

Fermat is a lunar impact crater located to the west of the Rupes Altai escarpment. To the west-southwest is the larger crater Sacrobosco, and to the southwest is the irregular Pons. It is 39 kilometers in diameter and two kilometers deep. The rim is worn and somewhat irregular, but still possesses an outer rampart. (wikipedia entry)

A crater is a circular depression likely created by an impact event. On the Moon they are named after deceased scientists, polar explorers, astronauts or cosmonauts.