Katchalsky (Moon)

Named after Katzir-Katchalsky, Aharon - Polish-Israeli chemist (1914-1972).

Katchalsky lies to the southeast of the larger crater Lobachevskiy, and to the west of the prominent King. The outer rim is not quite circular, with outward bulges to the east and north, giving it a flat side along the northeastern edge. The rim is not markedly eroded, and the interior contains only a few tiny craterlets. (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.