Kepler 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 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 craters ...

that lies between the

Oceanus Procellarum Oceanus Procellarum ( la, Ōceanus procellārum, lit=Ocean of Storms) is a vast lunar mare on the western edge of the near side of the Moon. It is the only one of the lunar maria to be called an "Oceanus" (ocean), due to its size: Oceanus Proc ...

to the west and

Mare Insularum Mare Insularum (Latin ''īnsulārum'', the "sea of islands") is a lunar mare located in the Insularum basin just south of the western Mare Imbrium. The basin material is of the Lower Imbrian epoch, with the mare material of the Upper Imbrian epoc ...

in the east. To the southeast is the crater

Encke Encke may refer to: *Johann Franz Encke (1791–1865), a nineteenth-century German astronomer ** Encke (crater), a lunar crater ** Encke Division, a dark gap in the rings of Saturn **Comet Encke, a short-period comet ***Encke (horse) (2009–2014) ...

. Kepler is named for the 17th century German astronomer and mathematician

Johannes Kepler Johannes Kepler (; ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws ...

Description

Kepler is most notable for the prominent

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 covers the surrounding

mare A mare is an adult female horse or other equine. In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger. In Thoroughbred horse racing, a mare is defined as a female horse more than four ...

. The rays extend for well over 300 kilometers, overlapping the rays from other craters. Kepler has a small

rampart Rampart may refer to: * Rampart (fortification), a defensive wall or bank around a castle, fort or settlement Rampart may also refer to: * "O'er the Ramparts We Watched" is a key line from "The Star-Spangled Banner", the national anthem of the ...

of ejecta surrounding the exterior of its high rim. The outer wall is not quite circular, and possesses a slightly

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 toge ...

al form. The interior walls of Kepler are slumped and slightly

terrace Terrace may refer to: Landforms and construction * Fluvial terrace, a natural, flat surface that borders and lies above the floodplain of a stream or river * Terrace, a street suffix * Terrace, the portion of a lot between the public sidewalk a ...

d, descending to an uneven floor and a minor central rise. One of the rays from Tycho, when extended across the

, intersects this crater. This was a factor in the choice of the crater's name when

Giovanni Riccioli Giovanni Battista Riccioli, Society of Jesus, SJ (17 April 1598 – 25 June 1671) was an Italian astronomer and a Catholic church, Catholic priest in the Jesuit order. He is known, among other things, for his experiments with pendulums and with f ...

was creating his system of

lunar nomenclature Selenography is the study of the surface and physical features of the Moon (also known as geography of the Moon, or selenodesy). Like geography and areography, selenography is a subdiscipline within the field of planetary science. Historica ...

, as Kepler used the observations of

Tycho Brahe Tycho Brahe ( ; born Tyge Ottesen Brahe; generally called Tycho (14 December 154624 October 1601) was a Danish astronomer, known for his comprehensive astronomical observations, generally considered to be the most accurate of his time. He was k ...

while devising his three laws of planetary motion. On Riccioli's maps, this crater was named ''Keplerus'', and the surrounding skirt of higher

albedo Albedo (; ) is the measure of the diffuse reflection of sunlight, 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 ...

terrain was named ''Insulara Ventorum''. Due to its prominent rays, Kepler is mapped as part of the Copernican System.The geologic history of the Moon, 1987, Wilhelms, Don E.; with sections by McCauley, John F.; Trask, Newell J.

USGS The United States Geological Survey (USGS), formerly simply known as the 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, a ...

Professional Paper: 1348. Plate 11: Copernican System
online

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 Kepler. File:Kepler D crater 4144 h1.jpg, Kepler D crater

References

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External links

* {{Johannes Kepler Impact craters on the Moon Johannes Kepler