Idel'son (Moon)

Named after Naum Ilich Idel'son - Soviet astronomer (1885-1951).

Idel'son is a lunar crater on the far side. It lies just behind the southern lunar limb, in a region that is sometimes brought into view of the Earth due to libration. Idel'son is situated to the southwest of the huge walled plain Schrödinger. The northern rim is overlain by the larger crater Ganswindt, reversing the usual order of smaller craters on top of larger impacts usually seen. (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.