Väisälä (Moon)

Named after Yrjo Väisälä - Finnish astronomer (1891-1971).

Väisälä is a tiny lunar crater located on a rise in the Oceanus Procellarum. Sharing the same continental island are the brilliant crater Aristarchus to the south-southeast and Herodotus to the south-southwest. Väisälä lies just to the west of the Rupes Toscanelli fault line, and the Rimae Aristarchus rille system. To the southwest is the notable Vallis Schröteri cleft. (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.