French astronomer who discovered 15 comets and in 1784 published a list of 103 star clusters and nebulae. Objects on this list are given M (for Messier) numbers, which astronomers still use today, such as M1 (the Crab nebula) and M31 (the Andromeda galaxy).

Messier was born in Badonviller, Lorraine, and joined the Paris Observatory. Watching for the predicted return of Halley's comet, he was one of the first people to spot it, an experience that inspired him with the desire to go on discovering new comets for the rest of his life. Louis XV nicknamed him the 'Comet Ferret'.
But Messier's search was continually hampered by rather obscure forms which he came to recognize as nebulae. During the period 1760-84, therefore, he compiled a list of these nebulae and star clusters, so that he and other astronomers would not confuse them with possible new comets.