Philolaus 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 is located in the northern part of the
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
'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
Anaxagoras (; grc-gre, Ἀναξαγόρας, ''Anaxagóras'', "lord of the assembly"; 500 – 428 BC) was a Pre-Socratic Greek philosopher. Born in Clazomenae at a time when Asia Minor was under the control of the Persian Empire, ...
. It overlies the older and heavily worn Philolaus C to the south.
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
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 ...
s with a sharp-edged rim in locations where slumping has occurred. On the exterior of the rim is an outer
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 ...
that extends outwards for nearly half a crater diameter in all directions. The crater has a
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 ...
, and is consequently 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
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.
External links
Twin Peaks Lunar Photo of the Day, March 4, 2006
References
*
*
*
*
*
*
*
*
*
*
*
*
{{refend
Impact craters on the Moon