Harlan (crater)

Harlan
Coordinates	38°30′S79°30′E / 38.5°S 79.5°E Coordinates: 38°30′S79°30′E / 38.5°S 79.5°E
Diameter	65 km
Depth	Unknown
Colongitude	282° at sunrise
Eponym	Harlan J. Smith

Last updated August 08, 2019

Harlan is a lunar impact crater near the southeastern limb of the Moon. It is located just to the northeast of the crater Marinus. To the northeast is the flooded walled plain Abel, and to the southeast is Mare Australe.

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 has a worn outer rim, with a crater attached to the northeastern rim and an irregular southern edge. The inner wall has slumped to form a shelf along the northwestern side. The interior floor has been resurfaced by basaltic lava, producing a level, nearly featureless surface with a lower albedo than its surroundings.

Basalt A magnesium- and iron-rich extrusive igneous rock

Basalt is a mafic extrusive igneous rock formed from the rapid cooling of magnesium-rich and iron-rich lava exposed at or very near the surface of a terrestrial planet or a moon. More than 90% of all volcanic rock on Earth is basalt. Basalt lava has a low viscosity, due to its low silica content, resulting in rapid lava flows that can spread over great areas before cooling and solidification. Flood basalt describes the formation in a series of lava basalt flows.

Lava is molten rock generated by geothermal energy and expelled through fractures in planetary crust or in an eruption, usually at temperatures from 700 to 1,200 °C. The structures resulting from subsequent solidification and cooling are also sometimes described as lava. The molten rock is formed in the interior of some planets, including Earth, and some of their satellites, though such material located below the crust is referred to by other terms.

Albedo is the measure of the diffuse reflection of solar radiation out of the total solar radiation received by an astronomical body. It is dimensionless and measured on a scale from 0 to 1.

Harlan was previously designated Marinus D before being assigned its current name by the IAU.

The International Astronomical Union is an international association of professional astronomers, at the PhD level and beyond, active in professional research and education in astronomy. Among other activities, it acts as the internationally recognized authority for assigning designations and names to celestial bodies and any surface features on them.

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Anders is a worn lunar impact crater that is located in the southern hemisphere on the far side of the Moon. It lies just to the southeast of the outer rim of the huge walled basin named Apollo. To the south-southeast is the crater Leavitt.

Doppler is a lunar impact crater named for Christian Doppler that is located at the southern edge of the walled plain Korolev, on the far side of the Moon. To the east are the craters Das and Galois. Farther to the southwest of Doppler is Mohorovičić.

Abel is an ancient lunar impact crater that lies near the southeast limb of the Moon's near side. It is located to the south of the crater Barnard, at the northwest edge of the Mare Australe.

Boss is a lunar impact crater that is located along the northeast rim of the Moon's near side. Due to its location, the crater is viewed from the side by observers on the Earth, and its visibility is subject to libration effects.

Beals is a lunar impact crater that is located near the eastern limb of the Moon, and lies across the southwestern rim of the crater Riemann. From the Earth the crater is viewed nearly from on edge, and is best seen during favorable librations. To the west is the large walled plain Gauss.

Dawson is a lunar impact crater that lies on the southern hemisphere on the far side of the Moon. It lies across a crater triplet: the southeast rim is intruding into the crater Alekhin; the northwest rim also intrudes into the larger satellite crater Dawson V, and the northeast rim is attached to the comparably sized Dawson D. To the south of this formation is the large crater Zeeman. West of Dawson is the crater Crommelin, and to the north lies Fizeau.

Biela is a lunar impact crater that is located in the rugged highlands of the southeastern Moon. It is named after Austrian astronomer Wilhelm von Biela. The crater lies to the east of Rosenberger, to the southeast of the Watt–Steinheil double crater.

Carmichael is a lunar impact crater that is located along the eastern edge of the Sinus Amoris, in the northeastern quadrant of the Moon's near side. Its diameter is 20 km. It was named after American psychologist Leonard Carmichael. It lies within a couple of crater diameters south-southwest of the smaller crater Hill. Further to the east-northeast is the prominent crater Macrobius. Carmichael was designated Macrobius A before being given its current name by the IAU.

Casatus is a lunar impact crater that is located near the southern limb of the Moon. The north-northeast rim of the crater overlies a portion of the slightly larger crater Klaproth. Along the western rim, Casatus A intrudes somewhat into the interior, producing an inward-bowing rim. To the southeast of Casatus is Newton.

Damoiseau is a lunar impact crater that is located just to the west of the Oceanus Procellarum, in the western part of the Moon's near side. It lies due east of the prominent crater Grimaldi, a walled plain with a distinctive dark floor. Due south of Damoiseau is the crater Sirsalis.

Marinus is a lunar impact crater that is located near the southeastern limb of the Moon. At this location it is viewed at an oblique angle from the Earth, limiting the amount of detail that can be observed. It lies due north of the slightly larger and dark-floored crater Oken. To the east is the northern part of the Mare Australe.

Carver is a lunar impact crater that is located on the far side of the Moon, due east of the walled plain Van der Waals. To the northeast is the crater Rosseland, and to the south-southeast lies Kozyrev.

Cichus is a lunar impact crater that lies in the southwestern part of the Moon, at the eastern edge of Palus Epidemiarum. Just to the northeast and nearly contacting the rim is the lava-flooded crater remnant Weiss. The crater is named after Italian astronomer Cecco d'Ascoli.

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.

Comstock is a lunar impact crater that is located on the far side of the Moon. It lies to the northeast of the walled plain Fersman, and north of the crater Weyl.

Einthoven is a lunar impact crater that is located on the far side of the Moon. It is located beyond the region of the surface that is sometimes brought into view due to libration, and so can not be viewed from the Earth. Einthoven is located to the northeast of the huge walled plain Pasteur.

Fourier is a lunar impact crater that is located in the southwestern part of the Moon's near side, just to the southeast of the crater Vieta. To the northeast is the Mare Humorum. The rim of this crater is roughly circular, but appears oval when viewed from the Earth due to foreshortening.

Donner is a lunar impact crater on the far side of the Moon. It is located just to the northeast of the Mare Australe, behind the southeastern limb of the Moon. During favorable librations this part of the lunar surface can be brought into view of the Earth, but the site is viewed from the edge and so not much detail can be seen.

Emden is a lunar impact crater that is located in the northern hemisphere on the far side of the Moon. It is named after Jacob Robert Emden (1862-1940).

Frost is a lunar impact crater that is attached to the southern rim of the walled plain Landau, and lies on the far side of the Moon. Just to the east is Petropavlovskiy, and to the northeast along the edge of Landau is Razumov. The crater Douglass is located less than a crater diameter to the west-southwest.

References

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Blue, Jennifer (July 25, 2007). "Gazetteer of Planetary Nomenclature". USGS . Retrieved 2007-08-05.
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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.
Moore, Patrick (2001). On the Moon. Sterling Publishing Co. ISBN 978-0-304-35469-6.
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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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Coordinates	38°30′S79°30′E / 38.5°S 79.5°E / -38.5; 79.5 Coordinates: 38°30′S79°30′E / 38.5°S 79.5°E / -38.5; 79.5
Diameter	65 km
Depth	Unknown
Colongitude	282° at sunrise
Eponym	Harlan J. Smith