Lambert (lunar crater)

This article is about the crater on the Moon. For the crater on Mars, see Lambert (Martian crater).
Lambert
Lambert from Apollo 15. NASA photo.
Coordinates25°48′N 21°00′W / 25.8°N 21.0°W / 25.8; -21.0
Diameter30 km
Depth2.7 km
Colongitude21° at sunrise
EponymJohann Heinrich Lambert
Lambert on a later orbit of Apollo 15. Most of Lambert R is visible as the circular structure south of Lambert.
Ghost crater Lambert R (photo by Apollo 17).

Lambert is a lunar impact crater on the southern half of the Mare Imbrium basin. It was named after Swiss polymath Johann Heinrich Lambert.[1] It lies to the east and somewhat south of the slightly larger crater Timocharis. To the south is the smaller Pytheas, and some distance to the west-southwest is Euler.

The crater is relatively easy to locate due to its isolated position on the mare. It has an outer rampart, terraced inner walls, and a rough interior that has a comparable albedo to its surroundings. Instead of a central peak, a small craterler lies at the midpoint of the interior.

Just to the south of Lambert's ramparts is the lava-covered rim of Lambert R, a crater that is almost completely covered by the mare. The diameter of this ghost crater is larger than Lambert, but it is difficult to spot except when the Sun is at a very low angle, casting long shadows.

Lambert is a crater of Eratosthenian age.[2]

  1. ^ "Lambert (lunar crater)". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program.
  2. ^ The geologic history of the Moon. USGS Professional Paper 1348. By Don E. Wilhelms, John F. McCauley, and Newell J. Trask. U.S. Government Printing Office, Washington: 1987. Table 12.2.