Named after the well-known French mathematician and comet hunter of the 18th century, Charles Messier, this pair of elongated craterlets measuring 11 and 13 km in length and 9 km in width on the western half of Mare Fecundidatis are a stunning pair for a variety of reasons. As indicated by the image below, a ray pattern to the west of both craters suggests an impact from east to west which occurred at a low and oblique angle. Furthermore, careful examination of the westernmost crater of this pair, Messier A, indicates the presence of a "lip" to its immediate west which is the remaining rim of an earlier crater which, for the most part, was obliterated by the latter impact leading to the formation of these new craters. Craters Messier and Messier A are relatively young and are believed to be 1.1 billion years of age or less. The ejecta material producing the ray to the west of Messier A is a stunning sight and readily visible with most magnifications.