Philolaus (crater)

Philolaus
	Lunar Orbiter 4 image
Coordinates	72°06′N32°24′W / 72.1°N 32.4°W Coordinates: 72°06′N32°24′W / 72.1°N 32.4°W
Diameter	70 km
Depth	3.4 km
Colongitude	30° at sunrise
Eponym	Philolaus

Last updated August 09, 2019

Philolaus is a lunar impact crater that is located in the northern part of the Moon's near side. It lies within one crater diameter to the east-southeast of the flooded crater Anaximenes, and to the west of the smaller Anaxagoras. It overlies the older and heavily worn Philolaus C to the south.

Lunar craters are impact craters on Earth's Moon. The Moon's surface has many craters, almost all of which were formed by impacts.

An impact crater is an approximately circular depression in the surface of a planet, moon, or other solid body in the Solar System or elsewhere, formed by the hypervelocity impact of a smaller body. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Impact craters range from small, simple, bowl-shaped depressions to large, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth.

Earth's Moon is an astronomical body that orbits the planet and acts as its only permanent natural satellite. It is the fifth-largest satellite in the Solar System, and the largest among planetary satellites relative to the size of the planet that it orbits. The Moon is, after Jupiter's satellite Io, the second-densest satellite in the Solar System among those whose densities are known.

This crater retains a well-defined form that has not changed significantly since it was originally created. The outer rim edge is roughly circular, but with a somewhat irregular edge that displays signs of slumping. The most notable slump is a triangular area along the eastern rim. The inner wall of the crater has a complex system of terraces with a sharp-edged rim in locations where slumping has occurred. On the exterior of the rim is an outer rampart that extends outwards for nearly half a crater diameter in all directions. The crater has a ray system, and is consequently mapped as part of the Copernican System.^[1]

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 of their originating crater, and are often accompanied by small secondary craters formed by larger chunks of ejecta. Ray systems have been identified on the Moon, Earth, Mercury, and some moons of the outer planets. Originally it was thought that they existed only on planets or moons lacking an atmosphere, but more recently they have been identified on Mars in infrared images taken from orbit by 2001 Mars Odyssey's thermal imager.

The Copernican Period in the lunar geologic timescale runs from approximately 1.1 billion years ago to the present day. The base of the Copernican period is defined by impact craters that possess bright optically immature ray systems. The crater Copernicus is a prominent example of rayed crater, but it does not mark the base of the Copernican period.

The interior floor is irregular with rough areas about the center and to the northeast. There is no single central peak, but rather a pair of peaks offset to the south and the east of the middle. There is also a smaller ridge pair offset to the northwest. The flattest part of the interior floor is in the northeast of the crater interior. The floor is not significantly marked by impacts.

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 Philolaus.

Philolaus	Latitude	Longitude	Diameter
B	69.6° N	24.3° W	11 km
C	71.1° N	32.7° W	95 km
D	73.9° N	27.8° W	91 km
E	69.6° N	18.7° W	12 km
F	68.1° N	18.3° W	8 km
G	69.0° N	23.6° W	95 km
U	75.0° N	33.0° W	13 km
W	75.6° N	35.9° W	17 km

External links

Twin Peaks, Lunar Photo of the Day, March 4, 2006

Related Research Articles

Anaximenes is a low-rimmed lunar impact crater near the north-northwest limb of the Moon. It lies to the west of the crater Philolaus, and northeast of Carpenter. To the northwest is Poncelet, close to the visible edge of the Moon.

Anaxagoras is a young lunar impact crater that is located near the north pole of the Moon. It lies across the larger and more heavily worn crater Goldschmidt. To the south-southeast is Epigenes, and due south is the worn remains of Birmingham.

Rutherfurd is a lunar impact crater located entirely within the southern rim of the much larger crater Clavius. The crater Porter is located to the north-northeast of Rutherfurd, on the northeastern rim of Clavius. Rutherfurd forms the larger member in an arcing chain of craters of decreasing size that curves across the floor of Clavius. The craters in this chain do not appear to be the same age, so this formation is most likely random in nature.

Hevelius is a low-rimmed lunar impact crater that lies at the western edge of the Oceanus Procellarum, named after the astronomer Johannes Hevelius. The smaller but prominent crater Cavalerius is joined to the northern rim by low ridges. Due south of Hevelius is the crater Lohrmann and the dark-hued Grimaldi.

Autolycus is a lunar impact crater that is located in the southeast part of Mare Imbrium. The crater is named after the ancient Greek astronomer Autolycus of Pitane. West of the formation is Archimedes, a formation more than double the size of Autolycus. Just to the north is Aristillus, and the outer ramparts of these two craters overlap in the intermediate stretch of the lunar mare.

Eudoxus is a prominent lunar impact crater that lies to the east of the northern tip of the Montes Caucasus range. It is named after the Greek astronomer Eudoxus of Cnidus. It is located to the south of the prominent crater Aristoteles in the northern regions of the visible Moon. To the south is the ruined formation of Alexander, and the small crater Lamèch lies to the southwest.

Ohm is a lunar impact crater that is located on the far side of the Moon. It lies to the south of the crater Comrie, and the satellite crater Comrie K is attached to Ohm's northeastern rim. To the northwest is the larger Shternberg, and to the southwest is Kamerlingh Onnes.

Fabry is a large lunar impact crater of the form termed a walled plain. It is located on the far side of the Moon, just beyond the northeastern limb. Parts of this area are sometimes brought into view by the effects of libration, but the terrain is seen from the edge and so not much in the way of detail can be observed.

Carpenter is a lunar impact crater in the northern part of the Moon, relatively close to the limb. At this position the crater is foreshortened and appears oval in shape. It is, however, very nearly circular in outline. The outer rampart to the south is adjoined to the old crater Anaximander, and the satellite formation Anaximander B lies along the western rim. To the northeast is Anaximenes.

Dryden is a lunar impact crater that is located on the southern hemisphere on the far side of the Moon. It lies within the huge walled plain called Apollo, and is one of several features within that basin named after people associated with the Apollo program. Apollo itself has an inner ring, and Dryden is attached to the west-northwest part of that circular mountain formation. To the south of Dryden along the same range is the crater Chaffee.

Pasteur is a large lunar impact crater, approximately 233 kilometers in diameter, belonging to the category termed a walled plain. It was named after French chemist and microbiologist Louis Pasteur. It lies on the far side of the Moon as seen from the Earth, just beyond the eastern limb. The vicinity of this crater is occasionally brought into view from Earth due to librations, although not much detail can be seen.

Carnot is a large crater in the northern part of the Moon's far side. It intrudes into the southern rim of the huge walled plain Birkhoff. To the west-southwest of Carnot is the crater Paraskevopoulos.

Crookes is a lunar impact crater that lies on the Moon's far side as seen from the Earth. It lies just to the southwest of the giant crater Korolev. To the southwest of Crookes is McKellar.

Lyman is a lunar impact crater that lies in the southern hemisphere on the far side of the Moon. It is located to the south of the huge walled plain Poincaré, and to the northeast of Schrödinger, another walled plain. To the east-southeast is the larger crater Minnaert.

Stoney is an impact crater on the Moon, located in the southern part of its far side, approximately 47.5 kilometers in diameter. In 1970, it was named by IAU's Working Group for Planetary System Nomenclature after Anglo-Irish physicist George Johnstone Stoney (1826–1911). It lies to the southeast of the crater Baldet and to the east of Bhabha.

Drebbel is a small lunar impact crater named after Cornelius Drebbel that is located to the northeast of the large walled plain Schickard, in the southwestern part of the Moon. Further to the northeast is the Lacus Excellentiae and the small crater Clausius.

Das is a lunar impact crater on the far side of the Moon. It is located to the northwest of the walled plain Chebyshev. To the southwest of Das is the irregular crater Mariotte, and Von der Pahlen lies to the east-northeast. The crater was named after Indian astronomer Amil Kumar Das.

Finsen is a lunar impact crater that is located in the southern hemisphere, on the Moon's far side. It is attached to the southeastern exterior of the walled plain Leibnitz, and the ejecta from Finsen covers the southeastern part of Leibnitz's interior floor. To the southwest of Finsen is another walled plain, Von Kármán, partly overlain by Leibnitz.

Necho is a lunar impact crater on the far side of the Moon, and therefore cannot be seen directly from the Earth. It lies to the northeast of the larger crater Langemak, about a crater diameter to the south-southwest of Bečvář and further east is Love.

Nernst is a lunar impact crater that lies on the far side of the Moon, just beyond the northwestern limb. It lies across the northern part of the larger walled plain Lorentz, and intrudes slightly into the northwestern rim of the crater Röntgen.

References

↑ The geologic history of the Moon, 1987, Wilhelms, Don E.; with sections by McCauley, John F.; Trask, Newell J. USGS Professional Paper: 1348. Plate 11: Copernican System (online)

Andersson, L. E.; Whitaker, E. A. (1982). NASA Catalogue of Lunar Nomenclature. NASA RP-1097.
Blue, Jennifer (July 25, 2007). "Gazetteer of Planetary Nomenclature". USGS . Retrieved 2007-08-05.
Bussey, B.; Spudis, P. (2004). The Clementine Atlas of the Moon. New York: Cambridge University Press. ISBN 978-0-521-81528-4.
Cocks, Elijah E.; Cocks, Josiah C. (1995). Who's Who on the Moon: A Biographical Dictionary of Lunar Nomenclature. Tudor Publishers. ISBN 978-0-936389-27-1.
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Menzel, D. H.; Minnaert, M.; Levin, B.; Dollfus, A.; Bell, B. (1971). "Report on Lunar Nomenclature by the Working Group of Commission 17 of the IAU". Space Science Reviews. 12 (2): 136–186. Bibcode:1971SSRv...12..136M. doi:10.1007/BF00171763.
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Webb, Rev. T. W. (1962). Celestial Objects for Common Telescopes (6th revised ed.). Dover. ISBN 978-0-486-20917-3.
Whitaker, Ewen A. (1999). Mapping and Naming the Moon. Cambridge University Press. ISBN 978-0-521-62248-6.
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Ewen Adair Whitaker was a British-born astronomer who specialized in lunar studies. During World War II he was engaged in quality control for the lead sheathing of hollow cables strung under the English Channel as part of the "Pipe Line Under The Ocean" Project (PLUTO) to supply gasoline to Allied military vehicles in France. After the war, he obtained a position at the Royal Greenwich Observatory working on the UV spectra of stars, but became interested in lunar studies. As a sideline, Whitaker drew and published the first accurate chart of the South Polar area of the Moon in 1954, and served as director of the Lunar Section of the British Astronomical Association.

The National Aeronautics and Space Administration is an independent agency of the United States Federal Government responsible for the civilian space program, as well as aeronautics and aerospace research.

The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization has four major science disciplines, concerning biology, geography, geology, and hydrology. The USGS is a fact-finding research organization with no regulatory responsibility.

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[1] The geologic history of the Moon, 1987, Wilhelms, Don E.; with sections by McCauley, John F.; Trask, Newell J. USGS Professional Paper: 1348. Plate 11: Copernican System (online)

Lunar Orbiter 4 image
Coordinates	72°06′N32°24′W / 72.1°N 32.4°W / 72.1; -32.4 Coordinates: 72°06′N32°24′W / 72.1°N 32.4°W / 72.1; -32.4
Diameter	70 km
Depth	3.4 km
Colongitude	30° at sunrise
Eponym	Philolaus

Philolaus (crater)

Contents

Satellite craters

External links

Related Research Articles

References