Gullstrand (Moon)

Named after Allvar Gullstrand - Swedish ophthalmologist; Nobel laureate (1862-1930).

Gullstrand is a lunar impact crater that lies on the northern hemisphere. About one crater diameter to the southeast is the larger crater Perrine. To the west-southwest is Quetelet. This crater has a circular rim that is well-defined, and has only been moderately worn. (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.