The crater is located at the southeastern edge of the Aristarchus plateau, an elevated area that contains a number of volcanic features, such as sinuous rilles. This area is also noted for the large number of reported transient lunar phenomena, as well as recent emissions of radon gas as measured by the Lunar Prospector spacecraft.
Aristarchus was originally named after the Greek astronomer Aristarchus of Samos by the Italian map maker Giovanni Riccioli. His work Almagestum novum ("New Almagest"), published in 1651, gave the spot-shaped telescopic features (later called craters) eponyms of noted astronomers and philosophers. Although it was already widely adopted, the name didn't become an official international standard until a vote by the IAU General Assembly in 1935.
The main reason for the crater's brightness is that it is a young formation, approximately 450 million years old, and the solar wind has not yet had time to darken the excavated material by the process of space weathering. The impact occurred following the creation of the ray crater Copernicus, but before the appearance of Tycho.
The brightest feature of this crater is the steep central peak. Sections of the interior floor appear relatively level, but Lunar Orbiter photographs reveal the surface is covered in many small hills, streaky gouges, and some minor fractures. The crater has a terraced outer wall, roughly or polygonal in shape, and covered in a bright blanket of ejecta. These spreads out into bright rays to the south and south-east, suggesting that Aristarchus was most likely formed by an oblique impact from the northeast, and their composition includes material from both the Aristarchus plateau and the lunar mare.
Spectra taken of this crater during the Clementine mission were used to perform mineral mapping. The data indicated that the central peak is a type of rock called anorthosite, which is a slow-cooling form of igneous rock composed of plagioclase feldspar. By contrast the outer wall is troctolite, a rock composed of equal parts plagioclase and olivine.
The Aristarchus region was part of a Hubble Space Telescope study in 2005 that was investigating the presence of oxygen-rich glassy soils in the form of the mineral ilmenite. Baseline measurements were made of the Apollo 15 and Apollo 17 landing sites, where the chemistry is known, and these were compared to Aristarchus. The Hubble Advanced Camera for Surveys was used to photograph the crater in visual and ultraviolet light. The crater was determined to have especially rich concentrations of ilmenite, a titanium oxide mineral that could potentially be used in the future by a lunar settlement for extracting oxygen.
|B||26.3° N||46.8° W||7 km|
|D||23.7° N||42.9° W||5 km|
|F||21.7° N||46.5° W||18 km|
|H||22.6° N||45.7° W||4 km|
|N||22.8° N||42.9° W||3 km|
|S||19.3° N||46.2° W||4 km|
|T||19.6° N||46.4° W||4 km|
|U||19.7° N||48.6° W||4 km|
|Z||25.5° N||48.4° W||8 km|
The following craters have been renamed by the IAU.