(IAU Directions) MAIRAN.--A bright ring-plain of irregular shape, 25 miles in diameter, on the W. of The Heraclides Promontory. The border, especially on the W., varies considerably in altitude, as is evident from its shadow at sunrise; at one peak on the E. it is said to attain a height of more than 15,000 feet above the interior. There is a very minute crater on the crest of the S. wall, down the inner slope of which runs a rill-like valley. About halfway down the inner face of the W. wall are two other small craters, connected together by a winding valley. These features may be seen under morning illumination, when about one-fourth of the floor is in sunlight. Schroter is the only selenographer who gives Mairan a central mountain. In this he is right. I have seen without difficulty on several occasions a low hill near the centre. The formation is surrounded by a number of conspicuous craters and crater-pits. On the N. there is a short rill-like valley, and another, much coarser, on the S.
- IAU page: Mairan
- Depth data from Kurt Fisher database
- Westfall, 2000: 2.67 km
- Viscardy, 1985: 3.4 km
- Cherrington, 1969: 3.41 km
- From the shadows in LO-IV-158H, the terrace along the upper east rim of Mairan is 1000-1500 m tall. Obviously, the crater as a whole is deeper than that. - Jim Mosher
- Exterior impact melt deposits most extensive to SW, max of ~8 km beyond rim (Hawke and Head, 1977).
- Mairan T, a distinct bright dome-like formation between Rima Sharp and Mairan itself (west of Mairan, in Sinus Roris) was photographed during the mission of Apollo 15. There are four orbital Hasselblads of Mairan T. One of them is AS15-93-12732. Mairan T is the bright dome with top-crater, below the horizon. Research: Danny Caes.
- Satellite craters Mairan A and G are on the ALPO list of bright ray craters.
- TSI = 30, CPI = 25, FI = 20; MI =75 Smith and Sanchez, 1973
- Jean Jacques d'Ortous de Mairan (November 26, 1678 - February 20, 1771) was a French geophysicist. In 1698 he went to Paris to study mathematics and physics. In 1729 he devised an experiment showing the existence of a circadian rhythm in plants, presumably originating from an endogenous clock. In 1731 he observed a nebulosity around a star near the Orion nebula. This was later designated M43.
- According to Whitaker (p. 218), this name was introduced by Schröter.
- The name MAIRAN seems to be rather difficult to write, because it was printed as MARIAN on page 5 in the 21st Century Atlas of the Moon (2012). Typographical error discovered by Howard Eskildsen. The same error was made on LAC 24 of the Clementine Atlass first edition of 2004: "'MARIAN E" instead of MAIRAN E.- DannyCaes Jan 25, 2013
- Mairan Tholus (an unofficial name for the unique dome-like formation Mairan T west of Mairan itself) - DannyCaes Sep 19, 2015
- Tran, T. et al (2011). Morphology of Lunar Volcanic Domes from LROC – 42nd LPSC Conference (Mar), 2011.