Chaplygin (Moon)

Named after Sergei Alekseevich Chaplygin - Soviet mathematician, engineer (1869-1942).

Chaplygin is a large lunar impact crater that lies on the far side. It is located to the southeast of the huge walled plain Mendeleev, about mid-way. It is about the same size as Albategnius on the near side. The rim of this crater is roughly circular, but with an uneven edge. (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.