Proclus is a young lunar

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 ...

located to the west of the Mare Crisium on the east shore of the Palus Somni. Its diameter is 27 km and it was named after 5th century Greek mathematician, astronomer and philosopher

Proclus Proclus Lycius (; 8 February 412 – 17 April 485), called Proclus the Successor (, ''Próklos ho Diádokhos''), was a Greek Neoplatonist philosopher, one of the last major classical philosophers of late antiquity. He set forth one of th ...

. 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 made up of line segments connected to form a closed polygonal chain. The segments of a closed polygonal chain are called its '' edges'' or ''sides''. The points where two edges meet are the polygon ...

al in shape, having the shape of a

pentagon In geometry, a pentagon () is any five-sided polygon or 5-gon. The sum of the internal angles in a simple polygon, simple pentagon is 540°. A pentagon may be simple or list of self-intersecting polygons, self-intersecting. A self-intersecting ...

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

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

, 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 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 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 Ejecta (; ) are particles ejected from an area. In volcanology, in particular, the term refers to particles including pyroclastic rock, pyroclastic materials (tephra) that came out of a explosive eruption, volcanic explosion and magma eruption v ...

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 The Apollo program, also known as Project Apollo, was the United States human spaceflight program led by NASA, which Moon landing, landed the first humans on the Moon in 1969. Apollo followed Project Mercury that put the first Americans in sp ...

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 Apollo 17 (December 7–19, 1972) was the eleventh and final mission of NASA's Apollo program, the sixth and most recent time humans have set foot on the Moon. Commander Gene Cernan and Lunar Module Pilot Harrison Schmitt walked on the Moon, ...

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; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...

. * 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

{{Commons category
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