Apollo is an enormous impact crater 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

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of the

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. This formation dwarfs the large crater

Oppenheimer Oppenheimer is a surname. Notable people with the surname include: In arts and media * Alan Oppenheimer (born 1930), American film actor * Andrés Oppenheimer (born 1951), Argentine author and journalist known for his analysis of Latin American p ...

that is located next to the western rim. The crater Barringer lies across the northern wall. To the southeast is the crater Anders, and Kleymenov is just to the east of the rim. Apollo is a double-ringed walled plain (or basin) whose inner ring is roughly half the diameter of the outer wall. Both the outer wall and the interior have been heavily worn and eroded by subsequent impacts, so that significant parts of the outer and inner walls now consist of irregular and incised sections of mountainous arcs. The interior floor is covered in a multitude of craters of various sizes, some of which have been named for people associated with the Apollo program or other

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

projects. Sections of Apollo's interior have been resurfaced with

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 ...

, leaving patches of the floor with a lower

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than the surroundings. There is a large patch of this lunar mare in the middle part of the inner ring, which contains some

ray system A ray system comprises radial streaks of fine '' ejecta'' thrown out during the formation of an impact crater, looking somewhat like many thin spokes coming from the hub of a wheel. The rays may extend for lengths up to several times the diameter ...

markings. A long stretch of the mare lies along the southern part of the crater. There is also a smaller section near the western rim. Prior to formal naming 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 ...

, the crater was known as ''Basin XVI''. File:Apollo basin topo.jpg, Topographic map File:Apollo basin GRAIL gravity.jpg, Gravity map based on GRAIL

Interior craters

Three craters are named after the crew of

Apollo 8 Apollo 8 (December 21–27, 1968) was the first crewed spacecraft to leave low Earth orbit and the first human spaceflight to reach the Moon. The crew orbited the Moon ten times without landing, and then departed safely back to Earth. These ...

. In the southeast part of Apollo is

Borman Borman is a surname. Notable people with the surname include: * Danleigh Borman (born 1985), South African soccer player *Frank Borman (1928–2023), American astronaut **The Frank Borman Expressway in Indiana named after him * Geoffrey D. Borman, ...

crater, named after commander Frank Borman. Near the southeastern margin of Apollo is Anders crater, named after William Anders. On the eastern margin is Lovell crater, named after Jim Lovell. Many craters within and adjacent to the Apollo impact have been named to honor deceased NASA employees. Dryden is attached to the west-northwestern exterior of the inner ring. Chaffee is a similar-sized crater that lies partly across the southwest section of the inner ring. Inside the inner ring are the craters Resnik, McAuliffe and Onizuka, and the Jarvis–

McNair McNair is a surname. Notable people with the surname include: *Alexander McNair (1775–1826), American politician *Andrew McNair, ringer of the Liberty Bell *Arnold McNair, 1st Baron McNair (1885–1975) *Barbara McNair (1934–2007), African-Ame ...

crater pair. The crater Smith lies across the northern part of the inner ring. In 2006 the IAU approved a proposal to name seven interior craters to honor the astronauts killed in the Space Shuttle ''Columbia'' disaster. Three of the crater names include the respective astronaut's first initials to distinguish them from the existing craters called Anderson,

Brown Brown is a color. It can be considered a composite color, but it is mainly a darker shade of orange. In the CMYK color model used in printing or painting, brown is usually made by combining the colors orange and black. In the RGB color model used ...

and

Clark Clark is an English language surname, ultimately derived from the Latin with historical links to England, Scotland, and Ireland ''clericus'' meaning "scribe", "secretary" or a scholar within a religious order, referring to someone who was educate ...

References

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External links

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