Gassendi (Moon)

Named after Pierre Gassendi - French astronomer, mathematician (1592-1655).

The formation has been inundated by lava during the formation of the mare, so only the rim and the multiple central peaks remain above the surface. A smaller crater Gassendi A intrudes into the northern rim, and joins a rough uplift at the northwest part of the floor. The crater pair bears a curious resemblance to a diamond ring. (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.