Bessel (Moon)

Named after Friedrich Wilhelm Bessel - German astronomer (1784-1846).

Bessel is a small lunar crater that is located in the southern half of the Mare Serenitatis. Despite its small size, this is the largest crater to lie entirely within the mare. It lies to the north-northeast of the crater Menelaus. This crater is circular and bowl-shaped with a rim that has a higher albedo than the floor or the surrounding mare. (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.