Guillaume (Moon)

Named after Charles Edouard Guillaume - Swiss metallurgist; Nobel laureate (1861-1938).

Guillaume is an old lunar crater 's northern hemisphere, and is located on the far side relative to the Earth. It lies just to the southeast of the slightly larger crater Perkin. This is a worn and eroded formation, with features that have been softened and rounded over time. A cluster of small craters covers most of the northeastern rim. (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.