Slipher (Moon)

Named after Earl Charles Slipher - American astronomer (1883-1964) and Vesto Melvin Slipher - American astronomer (1875-1969).

Slipher is a lunar impact crater, that is located in the northern latitudes on the far side. The crater overlies the southwestern outer rim of the much larger walled plain D'Alembert, and it occupies a portion of the interior floor of D'Alembert. To the south-southeast is the crater Langevin. Because it overlies D'Alembert, Slipher is a younger formation and it has undergone much less erosion. (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.