Chrétien 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 circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters ...

that is located in the southern

hemisphere Hemisphere refers to: * A half of a sphere As half of the Earth * A hemisphere of Earth ** Northern Hemisphere ** Southern Hemisphere ** Eastern Hemisphere ** Western Hemisphere ** Land and water hemispheres * A half of the (geocentric) celestia ...

on the

far side of the Moon The far side of the Moon is the lunar hemisphere that always faces away from Earth, opposite to the Near side of the Moon, near side, because of synchronous rotation in the Moon's orbit. Compared to the near side, the far side's terrain is ru ...

from the

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

. It lies due south of 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 old ...

, one of the few

maria Maria may refer to: People * Mary, mother of Jesus * Maria (given name), a popular given name in many languages Place names Extraterrestrial *170 Maria, a Main belt S-type asteroid discovered in 1877 *Lunar maria (plural of ''mare''), large, da ...

on the Moon's far side. The crater lies in the midpoint between the craters Garavito to the west-southwest and

Oresme Nicole Oresme (; c. 1320–1325 – 11 July 1382), also known as Nicolas Oresme, Nicholas Oresme, or Nicolas d'Oresme, was a French philosopher of the later Middle Ages. He wrote influential works on economics, mathematics, physics, astrology an ...

to the east-northeast, both of these being somewhat smaller than Chrétien. The crater has a low

albedo Albedo (; ) is the measure of the diffuse reflection of sunlight, solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body ...

interior floor, which has the same darker hue as the Mare Ingenii to the north. The irregular satellite crater Chrétien C, which shares the straight and narrow northeastern rim of Chrétien, is also covered with this dark

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

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 moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

. The outer rim of Chrétien is irregular in shape, with several other satellite craters intruding into the sides. The most notable of these are Chrétien S across the southwest rim, and Chrétien W attached to the northwest rim. The northern rim of Chrétien has a break that joins a small, irregular plain. This area has been resurfaced by the same lava flows that covered the interior of Chrétien. At the southern end, the inner wall forms a wide, irregular surface while the damaged rim bulges outward to the south. The crater was formally named in 1970 by the

IAU The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...

after French mathematician and astronomer

Henri Chrétien Henri Jacques Chrétien (1 February 1879, Paris – 6 February 1956, Washington, D.C.) was a French astronomer and an inventor. Born in Paris, France, his most famous inventions are: - the anamorphic widescreen process, using an anamorphic len ...

. Before 1970, the crater was known as ''Crater 427''.Lunar Farside Chart (LFC-1A)
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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 Chrétien.

References

* * * * * * * * * * * * Impact craters on the Moon {{Craters on the Moon: C-F