Lyapunov (Moon)

Named after Aleksandr Mikhailovich Lyapunov - Russian mathematician, engineer (1857-1918).

Lyapunov is a lunar crater named for Aleksandr Lyapunov that is located along the east-northeastern limb , and is viewed from the side by observers on Earth. The eastern rim of this crater just falls into the section called the far side, and visibility of this formation is affected by libration. This crater is attached to the south-southeastern rim of the larger walled plain Rayleigh. It is also attached to the western rim of the much larger walled plain Joliot, a formation that lies entirely on the far side. (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.