Descartes

About Descartes

Descartes is a heavily worn lunar impact crater that is located in the rugged south-central highlands of the Moon. To the southwest is the crater Abulfeda. Further to the west-northwest is Anděl crater, while Kant is located to the east=northeast.

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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 with the surviving outer walls to the northwest and southeast, forming the remains of an inner ring.

A section of the outer rim of Descartes is covered by a region that has a higher albedo than the surrounding surface. Low-altitude measurements by the Lunar Prospector showed that this patch is actually a magnetic anomaly—the strongest on the near side of the Moon. This magnetic field may be deflecting particles from the solar wind, and thus preventing the underlying surface from growing darker because of space weathering. This is similar to the process causing Reiner Gamma and other bright swirls such as those of Mare Marginis and Mare Ingenii.

About 50 kilometers to the north of this crater was the landing site of Apollo 16. The uneven region about the landing area is sometimes called the Descartes Highlands or the Descartes Mountains.

This formation is named after the French philosopher, mathematician and physicist René Descartes. His name was introduced with the lunar nomenclature of Johann H. von Mädler. Its designation was formally adopted by the International Astronomical Union in 1935.

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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 Descartes.

Descartes C and Dollond E during full moon

Immediately northeast of Descartes, the two bowl-shaped high albedo craters Descartes C and Dollond E seem to be connected by a bright looking oblong patch. This bright patch was called Caramuelis by the Flemish-Dutch selenographer Michael van Langren. North of van Langren's Caramuelis, Apollo 16's lunar module Orion landed between the small high albedo craterlets North Ray Crater and South Ray Crater. The couple of high albedo bowl-shaped craters Kant P and Kant Z, east of van Langren's Caramuelis, are sometimes erroneously seen as Apollo 16's North Ray Crater and South Ray Crater. Michael van Langren's bright Caramuelis and the high albedo bowl-shaped craters in the neighbourhood are also noticeable on the photographic version of chart LAC 78 (page 156) in The Clementine Atlas of the Moon (Ben Bussey / Paul D. Spudis).

Article from Wikipedia (CC BY-SA 4.0), where it is maintained by volunteer editors.

Notable quotes

“What I have given in the second book on the nature and properties of curved lines, and the method of examining them, is, it seems to me, as far beyond the treatment in the ordinary geometry, as the rhetoric of Cicero is beyond the a, b, c of children.”
— Letter to Marin Mersenne (1637) as quoted by D. E. Smith & M. L. Latham Tr. The Geometry of René Descartes (1925)
“Le bon sens est la chose du monde la mieux partagée : car chacun pense en être si bien pourvu, que ceux même qui sont les plus difficiles à contenter en toute autre chose, n'ont point coutume d'en désirer plus qu'ils en ont.”
— Good sense is, of all things among men, the most equally distributed; for every one thinks himself so abundantly provided with it, that those even who are the most difficult to satisfy in everything else, do not usually desire a larger measure of this quality than they already possess.
“It should be remembered that it was Descartes who systematised our Mathematical notation. He used the letters at the end of the alphabet as variables, and those at the beginning as constants, and he brought into general use our present system of indices. He also introduced the method of indeterminate co-efficients for the solution of equations.”
— Elizabeth Sanderson Haldane, Descartes: His Life and Times (1905) Ch. XVII. Descartes' Geometry
“The primary property of matter was indeed distinctly announced by Descartes in what he calls the "First Law of Nature": "That every individual thing, so far as in it lies, perseveres in the same state, whether of motion or of rest."”
— James Clerk Maxwell, Matter and Motion (1876)
“Descartes may have made a lot of mistakes, but he was right about this: you cannot doubt the existence of your own consciousness. That's the first feature of consciousness, it's real and irreducible. You cannot get rid of it by showing that it's an illusion in a way that you can with other standard illusions.”
— John Searle, "Our shared condition — consciousness", TED.com (May, 2013)
“His decipherment of Nature might be crude, yet he had the courage to insist that the mechanical sense could be made of the workings of Nature, throughout the realms of physics, chemistry, and even physiology. By reasserting the unity and rationality of Nature, he did as much as any man to put seventeenth-century scientists back on the intellectual road first trodden by the Greeks.”
— , , The Architecture of Matter (1962)

Quotes via Wikiquote (CC BY-SA), each with its original source.