Lat: 14.0°N, Long: 72.5°E, Diam: 39 km, Depth: 2.77 km, Rükl: 38
- The wonderful system of bright and dark "spokes" on the inner slopes of the cone-shaped crater Hansen A is noticeable near the right margin of Apollo 15's orbital ITEK-panoramic frame AS15-P-9151. Hansen A is located immediately west-southwest of Charles Wood's Lacus Risus Felis.
- Research Apollo 15's ITEK-frame: Danny Caes
Depth data from Kurt Fisher database
- Westfall, 2000: 2.77 km
- Cherrington, 1969: 1.49 km
- Named for Peter Andreas Hansen (December 8, 1795 - March 28, 1874), a Danish astronomer. The problems of gravitational astronomy engaged the chief part of Hansen's attention. He researched the mutual perturbations of Jupiter and Saturn. In 1838 he published a revision of the lunar theory, entitled Fundamenta nova investigationis, &c., and improved Tables of the Moon ("Hansen's Lunar Tables") based upon it were printed in 1857. Hansen twice visited England and was twice (in 1842 and 1860) the recipient of the Gold Medal of the Royal Astronomical Society. He communicated to that society in 1847 an able paper on a long-period lunar inequality (Memoirs Roy. Astr. Society, xvi. 465), and in 1854 one on the moon's figure, advocating the mistaken hypothesis of its deformation by a huge elevation directed towards the earth (ib. xxiv. 29). Hansen gave in 1854 the first intimation that the accepted distance of the sun was too great by some millions of miles (Month. Notices Roy. Astr. Soc. xv. 9), the error of J. F. Encke's result having been rendered evident through his investigation of a lunar inequality.
- Hansen is Catalog number 11 in Mary Blagg's Collated List and in the IAU's Named Lunar Formations. The name is attributed to Beer and Mädler, who do not appear to identify the honoree.
- Hansen B was called "Lower" by Wilkins and Moore, but the I.A.U. did not accept that name. William Lower was an English selenographer, and friend of Thomas Harriot circa 1610.
- Hansen B was also called "Olblatt" by Julius Heinrich Franz (mentioned in Named Lunar Formations). Research: Danny Caes.