A small, young crater made conspicuous by the bright ejecta which surrounds it. Unusually, instead of a ray system, Euclides has a smooth halo of ejecta called a nimbus (Latin for cloud) which extends almost to the Riphaeus Mountains to the east.

Photo: António Cidadão. His Home Page of Astrophotography includes stereograms, animations, and "Seven Craters a Week" from his forthcoming photographic lunar atlas.

Inconstant Moon