Geological Chronicle
Crüger lies in the rugged highlands southwest of Oceanus Procellarum, set northeast of the Darwin walled plain and just southeast of Lacus Aestatis. Spanning 45.94 kilometers across, the crater sits inside an older, eroded impact basin that extends 120 kilometers across the highland terrain.
Formed during the Lower Imbrian epoch, Crüger predates the excavation of the Mare Orientale basin to its west. Basaltic lava subsequent to the impact submerged its inner basin, burying the explosive source vents and creating a nearly level floor that ranks among the lowest-albedo surfaces on the Moon.
The floor contains only minimal overlying ejecta and is almost featureless, broken only by a 2.5-kilometer impact crater near its center alongside a few minor pits. Its low, circular outer rim remains largely intact, retaining its original geometry without substantial disruption from later impacts.
Giovanni B. Riccioli recorded the feature as Crugerus on his 1651 lunar map to honor the German mathematician Peter Crüger. The International Astronomical Union formally adopted the modern spelling in 1935.