MOON TOUR - LANGRENUS CRATER

This month, we help you find one of the Moon’s best hidden gems

The Moon has many ‘celebrity’ craters, like Copernicus, Tycho and Eratosthenes, which are big and bright enough to be obvious to the naked eye. However, these celebrities owe their fame to a stroke of good fortune: the bodies that blasted them out of the lunar surface millennia ago struck the face of the Moon pointing right at Earth. There are other craters that are just as big and interesting as Copernicus, but they are reduced to B- or C-list status because they were blasted out of areas not so well-placed for observation. Instead, we see them at an angle, foreshortened by the curve of the Moon’s limb. Langrenus is one such crater.

A 137-kilometre (85-mile) wide, six-kilometer (3.7-mile) deep hole, punched into the Moon by a massive asteroid impact millennia ago, Langrenus would rival great Copernicus in beauty if it had been formed near the centre of the Moon’s face. Sadly, it was blasted out of the eastern edge of Mare Fecunditatis, the ancient sea directly to the south of the dark eye socket of Mare Crisium, and so Langrenus’ beauty and apparent size are both greatly diminished, as it is almost on the Moon’s limb.