Thomson is a

lunar Lunar most commonly means "of or relating to the Moon". Lunar may also refer to: Arts and entertainment * ''Lunar'' (series), a series of video games * "Lunar" (song), by David Guetta * "Lunar", a song by Priestess from the 2009 album ''Prior t ...

impact crater An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal c ...

that is located within the

Mare Ingenii Mare Ingenii (Latin ''ingeniī'', the "Sea of Cleverness") is one of the few lunar mare features on the far side of the Moon. The mare sits in the Ingenii basin, which is of the Pre-Nectarian epoch, which lies in turn in the outer part of the o ...

on the

far side ''The Far Side'' is a single-panel comic created by Gary Larson and syndicated by Chronicle Features and then Universal Press Syndicate, which ran from December 31, 1979, to January 1, 1995 (when Larson retired as a cartoonist). Its surrealis ...

of the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

. Just to the northeast is the unusual merged crater formation of

Van de Graaff Van de Graaf, Van de Graaff or Van der Graaf may refer to: * Van de Graaff (crater), a lunar crater * Van de Graaf (surname), includes a list of people with the surname and its variants * Van de Graaff generator, an electrostatic generator * Van d ...

. On the northwest rim of the

mare A mare is an adult female horse or other equidae, equine. In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger. In Thoroughbred horse racing, a mare is defined as a female horse more th ...

O'Day O'Day is a surname of Irish origin. Notable people with the surname include: *Alan O'Day (1940–2013), American singer-songwriter *Anita O'Day (1919–2006), American jazz singer * Aubrey O'Day (born 1984), American singer, dancer, actress, songw ...

, and to the south-southwest is Obruchev on the southern shore of Mare Ingenii. In the past the crater was flooded by

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

, leaving only the outer rim intact. There are gaps in the eastern and western rims, leaving two "half-moon" mountainous formations facing each other across the relatively flat floor. There is a similar lava-flooded crater remnant attached to the southern rim of Thomson. The floor of Thomson has a number of secondary impacts that form short, linear streaks across the surface.

Satellite craters

By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Thomson.

References

* * * * * * * * * * * * {{refend Impact craters on the Moon