Foucault (Moon)

Named after Leon Foucault - French physicist (1819-1868).

Foucault is a small lunar impact crater that lies along the southern edge of Mare Frigoris, to the southeast of the crater Harpalus. The outer perimeter forms a somewhat irregular circle, with slight outward bulges to the south and northeast. The inner wall of the rim is not notably terraced, and slopes down directly to the uneven floor. (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.