Geminus (Moon)

Named after Geminus - Greek astronomer (unkn-c. 70 B.C.).

Geminus is a lunar impact crater that is located near the northeast limb of the visible Moon. In this position the crater appears oval in shape due to foreshortening, but it is actually more nearly circular in form. Notable nearby craters include Messala to the northeast, Bernoulli due east, and Burckhardt and Cleomedes to the south. The circular rim contain a number of outward notches, particularly to the north and east. (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.