Descartes (crater)
Encyclopedia
Descartes is a heavily worn lunar
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

 that is located in the rugged south-central highlands of the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

. To the southwest is the crater Abulfeda
Abulfeda (crater)
Abulfeda is a lunar impact crater located in the central highlands of the Moon. To the northeast is the crater Descartes, and to the south-southeast is Almanon. To the north is the crater Dollond. A chain of craters named the Catena Abulfeda runs between the southern rim of Abulfeda and the north...

. It is named after the French philosopher
French philosophy
French philosophy, here taken to mean philosophy in the French language, has been extremely diverse and has influenced Western philosophy as a whole for centuries, from the medieval scholasticism of Peter Abelard, through the founding of modern philosophy by René Descartes, to 20th century...

, mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....

 and physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...

 René Descartes
René Descartes
René Descartes ; was a French philosopher and writer who spent most of his adult life in the Dutch Republic. He has been dubbed the 'Father of Modern Philosophy', and much subsequent Western philosophy is a response to his writings, which are studied closely to this day...

.

The rim of Descartes survives only in stretches, and is completely missing in the north. The crater Descartes A lies across the southwest rim. The interior floor contains several curved ridges. These are concentric
Concentric
Concentric objects share the same center, axis or origin with one inside the other. Circles, tubes, cylindrical shafts, disks, and spheres may be concentric to one another...

 with the surviving outer walls to the northwest and southeast.

A section of the outer rim of Descartes is covered by a region that has a higher albedo
Albedo
Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...

 than the surrounding surface. Measurements by the Clementine spacecraft showed that this patch is actually a magnetic
Magnetism
Magnetism is a property of materials that respond at an atomic or subatomic level to an applied magnetic field. Ferromagnetism is the strongest and most familiar type of magnetism. It is responsible for the behavior of permanent magnets, which produce their own persistent magnetic fields, as well...

 anomaly—the strongest on the near side of the Moon. This magnetic field may be deflecting particles from the solar wind
Solar wind
The solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...

, and thus preventing the underlying surface from growing darker because of space weathering
Space weathering
Space weathering is a blanket term used for a number of processes that act on any body exposed to the harsh space environment. Airless bodies incur many weathering processes:* collisions of galactic cosmic rays and solar cosmic rays,* irradiation, implantation, and sputtering from solar wind...

.

About 50 kilometers to the north of this crater was the landing site of Apollo 16
Apollo 16
Young and Duke served as the backup crew for Apollo 13; Mattingly was slated to be the Apollo 13 command module pilot until being pulled from the mission due to his exposure to rubella through Duke.-Backup crew:...

. The uneven region about the landing area is sometimes called the Descartes Highlands
Descartes Highlands
The Descartes Highlands is an area of lunar highlands located on the near side that served as the landing site of the American Apollo 16 mission in early 1972...

or the Descartes Mountains.

Satellite craters

By convention these features are identified on lunar maps by placing the letter on the side of the crater mid-point that is closest to Descartes.
Descartes Latitude Longitude Diameter
A 12.1° S 15.2° E 16 km
C 11.0° S 16.3° E 4 km
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