Longomontanus is an ancient

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 ...

located in the rugged southern highlands to the southwest of the bright ray crater Tycho. Longomontanus is of the variety of large lunar formations called a "walled plain", although it is actually more of a circular depression in the surface. Because of its location, Longomontanus appears distinctly

oval An oval () is a closed curve in a plane which resembles the outline of an egg. The term is not very specific, but in some areas (projective geometry, technical drawing, etc.) it is given a more precise definition, which may include either one or ...

in shape due to foreshortening. To the southeast of Longomontanus is the even larger formation

Clavius Christopher Clavius, SJ (25 March 1538 – 6 February 1612) was a Jesuit German mathematician, head of mathematicians at the Collegio Romano, and astronomer who was a member of the Vatican commission that accepted the proposed calendar inve ...

, and to the east is Maginus. North of the rim is the irregular crater Montanari, which in turn is joined at its northern rim by

Wilhelm Wilhelm may refer to: People and fictional characters * William Charles John Pitcher, costume designer known professionally as "Wilhelm" * Wilhelm (name), a list of people and fictional characters with the given name or surname Other uses * Mount ...

. The wall of Longomontanus is heavily worn and incised by past impacts, and the rim is essentially level with the surrounding

terrain Terrain or relief (also topographical relief) involves the vertical and horizontal dimensions of land surface. The term bathymetry is used to describe underwater relief, while hypsometry studies terrain relative to sea level. The Latin word ...

. The northern rim especially is impacted with multiple overlapping craterlets. To the east of the rim is a semi-circular ridge that has the appearance of an overlapped crater rim. The crater floor of Longomontanus is relatively flat, with a low cluster of central peaks somewhat offset to the west. Longomontanus is one of the largest craters of Nectarian age.The geologic history of the Moon

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. By Don E. Wilhelms, John F. McCauley, and Newell J. Trask. U.S. Government Printing Office, Washington: 1987. Table 9-4.

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 Longomontanus.

References

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External links

* {{cite web , last = Wood , first = Chuck , date = December 30, 2007 , url = http://www.lpod.org/?m=20071230 , title = Splattered , publisher = Lunar Photo of the Day , access-date = 2008-01-02 , url-status = dead , archive-url = https://web.archive.org/web/20071231060800/http://www.lpod.org/?m=20071230 , archive-date = December 31, 2007 Impact craters on the Moon