Autolycus 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 in the southeast part of

Mare Imbrium Mare Imbrium (Latin ''imbrium'', the "Sea of Showers" or "Sea of Rains") is a vast lunar mare, lava plain within the Imbrium Basin on the Moon and is one of the larger craters in the Solar System. The Imbrium Basin formed from the collision ...

. The crater is named after the ancient Greek astronomer

Autolycus of Pitane Autolycus of Pitane (; c. 360 – c. 290 BC) was a Greek astronomer, mathematician, and geographer. He is known today for his two surviving works ''On the Moving Sphere'' and ''On Risings and Settings'', both about spherical geometry. Life Auto ...

. West of the formation is

Archimedes Archimedes of Syracuse ( ; ) was an Ancient Greece, Ancient Greek Greek mathematics, mathematician, physicist, engineer, astronomer, and Invention, inventor from the ancient city of Syracuse, Sicily, Syracuse in History of Greek and Hellenis ...

, a formation more than double the size of Autolycus. Just to the north is

Aristillus Aristyllus (; fl. c. 261 BC) was a Greek astronomer, presumably of the school of Timocharis (c. 300 BC). He was among the earliest meridian-astronomy observers. Six of his stellar declinations are preserved at Almajest 7.3. All are exa ...

, and the outer ramparts of these two craters overlap in the intermediate stretch of the

lunar mare The lunar maria ( ; mare ) are large, dark, basaltic plains on Earth's Moon, formed by lava flowing into ancient impact basins. They are less reflective than the "highlands" as a result of their iron-rich composition, and hence appear dark to ...

Description

The rim of Autolycus is somewhat irregular, although generally circular overall. It has a small outer rampart and an irregular interior with no central peak. It possesses a light

ray system In planetary geology, 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 ...

that extends for a distance of over 400 kilometers. Due to its rays, Autolycus is mapped as part of the Copernican System. Some of the ray material appears to overlay the flooded floor of Archimedes, and thus Autolycus is older than Archimedes. Aristillus (to the north), however, has rays that overlay both Autolycus and Archimedes, and thus it is the youngest of the three craters. The first man-made impact upon the Moon was when the

Luna 2 ''Luna 2'' (), originally named the Second Soviet Cosmic Rocket and nicknamed Lunik 2 in contemporaneous media, was the sixth of the Soviet Union's Luna programme spacecraft launched to the Moon, E-1 No.7. It was the first spacecraft Moon landi ...

probe crash-landed just to the west-southwest of the crater rim on September 13, 1959, according to the claim of one Hungarian astronomer who claimed to see an explosion of dust.

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 Autolycus.

Description

Satellite craters

Notes

References

External links