Geological Chronicle
Langmuir is an impact crater situated on the far side of the Moon, to the southwest of the Mare Orientale impact basin. Measuring 91.5 kilometers across, the crater lies between two larger structures: Chebyshev to the west-northwest and Brouwer to the east. Because Langmuir partly overlaps the rims of both neighbors, it represents the youngest feature in the grouping. Ejecta from Langmuir's outer rampart extends across and partly covers the southeastern floor of Chebyshev.
Dating to the Imbrian period of the lunar geologic timescale, the crater has avoided severe erosion and retains sharply defined structural features. Its western rim shows disruption where it superimposed the older margin of Chebyshev, marked by small craters at the northern and southern merger points. The inner southern wall is nearly twice as wide as the northern wall, shifting the interior floor toward the north.
Within the crater interior, the floor is relatively level in the western half and more uneven in the east. A central peak formation rises northeast of the midpoint, containing anorthosite with low mafic abundance. The crater is named for Irving Langmuir, an American physicist, chemist, and Nobel laureate.