Impact erosion leaves Gruemberger’s rim rounded

Feature Profile & Selenographic Data

Feature type

crater

Coordinates

67.04° S · 10.30° W

Diameter

91.5 km

IAU approval

1935/01/01 00:00:00

LAC quadrangle

LAC-137 · Moretus

Geological Chronicle

Gruemberger is an old impact crater in the Moon’s southern part. From Earth it appears oval because of foreshortening, but is actually relatively circular. It lies about 25 km north-northwest of Moretus; Cysatus intrudes into its eastern rim, and Clavius is about one and a half crater diameters to the north. The registry identifies its namesake as Christoph, an Austrian astronomer (1561–1636).

Minor impacts have steadily eroded the crater, leaving features along the rim and inner wall softened and rounded. Significant nearby impacts have covered the floor and sides with ejecta.

A multitude of tiny craterlets lines the inner wall. The satellite crater Gruemberger A lies inside Gruemberger, along the inner wall to the west-southwest. On lunar maps, satellite craters are identified by a letter placed on the side of the crater midpoint closest to Gruemberger.

Chronology & Exploration

1. Undated Rim and inner wall eroded

   Steady erosion from minor impacts softened and rounded features along the rim and inner wall.

2. Undated Ejecta covers floor and sides

   Significant impacts nearby covered the crater floor and sides with ejecta.

3. Undated Gruemberger A located

   The satellite crater lies inside Gruemberger along the inner wall to the west-southwest.

Scientific Sources & References

• IAU Gazetteer — Registry reference for identity, coordinates, diameter and name origin.
• Wikipedia: Gruemberger (crater) — Local source for the crater’s shape, setting, erosion and satellite crater.

Name Origin

Christoph; Austrian astronomer (1561-1636).