Proclus is a young lunar

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 crater ...

located to the west of the

Mare Crisium Mare Crisium (Latin ''crisium'', the "Sea of Crises") is a lunar mare located in the Moon's Crisium basin, just northeast of Mare Tranquillitatis. The basin is of the Pre-Imbrian period, 4.55 to 3.85 billion years ago. Characteristics Mare C ...

, on the east shore of the Palus Somni. Its diameter is 27 km. It was named after 5th century Greek mathematician, astronomer and philosopher

Proclus Proclus Lycius (; 8 February 412 – 17 April 485), called Proclus the Successor ( grc-gre, Πρόκλος ὁ Διάδοχος, ''Próklos ho Diádokhos''), was a Greek Neoplatonist philosopher, one of the last major classical philosophe ...

It lies to the south of the prominent, terraced crater

Macrobius Macrobius Ambrosius Theodosius, usually referred to as Macrobius (fl. AD 400), was a Roman provincial who lived during the early fifth century, during late antiquity, the period of time corresponding to the Later Roman Empire, and when Latin was ...

, and west-northwest of the lava-flooded Yerkes.

Description

The rim of Proclus is distinctly

polygon In geometry, a polygon () is a plane figure that is described by a finite number of straight line segments connected to form a closed '' polygonal chain'' (or ''polygonal circuit''). The bounded plane region, the bounding circuit, or the two t ...

al in shape, having the shape of a

pentagon In geometry, a pentagon (from the Greek language, Greek πέντε ''pente'' meaning ''five'' and γωνία ''gonia'' meaning ''angle'') is any five-sided polygon or 5-gon. The sum of the internal angles in a simple polygon, simple pentagon is ...

, and does not rise very far above the surrounding terrain. It has a high

albedo Albedo (; ) is the measure of the diffuse reflection of 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 that refl ...

, being second only to Aristarchus in brightness. The interior wall displays some slumping, and the floor is uneven with a few small rises from slump blocks. The crater has a notable

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 ...

that extends for a distance of over 600 kilometers. The rays display an asymmetry of form, with the most prominent being rays to the northwest, north-northeast, and northeast. There is an arc with no ejecta to the southwest. These features suggest an impact at a low angle. The rays indicate the crater is part of the Copernican System.Apollo 15 Preliminary Science Report (NASA SP-289), Chapter 25, Part J, ''Preliminary geologic map of the region around the candidate Proclus Apollo landing site'' by Don E. Wilhelms, 1972 A candidate landing site for the Apollo program was located about 100 km north-northeast of Proclus.Apollo 15 Preliminary Science Report (NASA SP-289), Chapter 25, Part K, ''Geologic sketch map of the candidate Proclus Apollo landing site'' by Baerbel Koesters Lucchitta, 1972 The site was rejected in favor of the geologically diverse Taurus-Littrow valley for the Apollo 17 mission.

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 Proclus. The following craters have been renamed 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 ...

. * Proclus F — ''See'' Crile (crater). File:Proclus D crater AS17-150-23052.jpg, Proclus D File:Proclus G crater AS17-M-2240.jpg, Proclus G

References

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External links

{{Commonscat
LTO-43C3 Proclus
Lunar Topographic Orthophotomap (LTO) Series
LTO-61B2 Glaisher
Lunar Topographic Orthophotomap (LTO) Series
Oblique closeup of Proclus crater
from Apollo 17 (Figure 147 o

(NASA SP-362), 1978)
Apollo 17 image AS17-150-23047
using the 70 mm Hasselblad. Impact craters on the Moon