Original NASA photography Apollo 11 S69-39539, Silver Print, A Kodak Paper, Vintage, Black Tab Number, 20.3 x 25.4 cm, Private Collection
Langrenus is an impact crater located on the eastern shore of the Mare Fecunditatis (Sea of Fertility in English). Despite its circular shape, this crater appears oval because of the radar foreshortening effect. In fact, this crater had not been the subject of observation of transient lunar phenomena in the past. However, since a series of lights on its soil was observed thanks to a telescope in 1992, the crater has become a site of significant observation. These gleams changed shape over time, which was probably due to gaseous releases.