Archimedes is a large lunar

impact crater An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal c ...

on the eastern edges of the

Mare Imbrium Mare Imbrium (Latin ''imbrium'', the "Sea of Showers" or "Sea of Rains") is a vast lunar mare, lava plain within the Imbrium Basin on the Moon and is one of the larger craters in the Solar System. The Imbrium Basin formed from the collision ...

. It was named by the IAU in 1935.

Description

The diameter of Archimedes is the largest of any crater on the

. The rim has a significant outer rampart brightened with ejecta and the upper portion of a terraced inner wall, but lacks the

ray system In planetary geology, 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 ...

associated with younger craters. A triangular promontory extends 30 kilometers from the southeast of the rim. Mare Imbrium Si map

The interior of the crater lacks a central peak, and is flooded with lava. It is devoid of significant raised features, although there are a few tiny meteor craters near the rim. Scattered wisps of bright ray material lie across the floor, most likely deposited by the impact that created Autolycus. Archimedes is a crater of Upper (Late) Imbrian age. Moon

Surroundings

To the south of Archimedes extends the Montes Archimedes, a mountainous region. On the southeastern rim is the Palus Putredinis, a lava-flooded plain containing a system of rilles named the Rimae Archimedes, which extends over 150 kilometers. North-northwest of Archimedes stand the

Montes Spitzbergen The Montes Spitzbergen (Spitzbergen Mountains) is a solitary mountain chain in the eastern Mare Imbrium of the Moon. It is located about 80 km to the north of the flooded crater Archimedes (crater), Archimedes. The range trends from south ...

, a string of peaks in the

. East of Archimedes is the crater Autolycus. Northeast of Archimedes is the prominent crater Aristillus. The lava plain between Archimedes, Aristillus, and Autolycus forms the Sinus Lunicus bay of

. A wrinkle ridge leads away from Archimedes toward the north-northwest, crossing this

mare A mare is an adult female horse or other equidae, 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 th ...

Names

Archimedes is named after the Greek scientist

Archimedes Archimedes of Syracuse ( ; ) was an Ancient Greece, Ancient Greek Greek mathematics, mathematician, physicist, engineer, astronomer, and Invention, inventor from the ancient city of Syracuse, Sicily, Syracuse in History of Greek and Hellenis ...

. Like many of the craters on the Moon's near side, it was given its name by Giovanni Riccioli, whose 1651 nomenclature system has become standardized. Earlier lunar cartographers had given the feature different names. Michael van Langren's 1645 map calls it "Roma" after the city of

Rome Rome (Italian language, Italian and , ) is the capital city and most populated (municipality) of Italy. It is also the administrative centre of the Lazio Regions of Italy, region and of the Metropolitan City of Rome. A special named with 2, ...

. Johannes Hevelius called it "Mons Argentarius" after Monte Argentario region in

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

Exploration

The stretch of lunar surface between Archimedes and Autolycus was the site of the crash-landing of the

Soviet The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

probe Luna 2. This was the first craft to reach the surface of the Moon, landing September 13, 1959.

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 Archimedes. The following craters have been renamed by the IAU. * Archimedes A - ''See'' Bancroft (crater). * Archimedes F - ''See'' MacMillan (crater). * Archimedes K - ''See'' Spurr (crater).

Gallery

File:Archimedes crater 4115 h1.jpg,

Lunar Orbiter 4 Lunar Orbiter 4 was a robotic U.S. spacecraft, part of the Lunar Orbiter program, Lunar Orbiter Program, designed to orbit the Moon, after the three previous orbiters had completed the required needs for Project Apollo, Apollo mapping and site s ...

image File:Imbrium map.png, Detail map of Mare Imbrium's features. Archimedes is the feature marked "G". File:M119883761 Archimedes LROC.png, LRO image of the contact of the crater wall (lower left) and the floor (upper right)

References

* * * * * * * * * * *

External links

*
High resolution lunar overflight video
by Seán Doran, based on LRO data, that passes over Archimedes about one third of the way through (se
album
for more) {{DEFAULTSORT:Archimedes (Crater) Impact craters on the Moon Mare Imbrium Archimedes