Messier, who was born in Badonviller in France, arrived in Paris in 1751 and was taken on as a clerical assistant by J. Delisle at the Naval Observatory sited in the Collège de Cluny. He quickly learned how to use the Observatory instruments and began a lifetime's obsessive search for comets. Dubbed the ‘comet ferret’ by Louis XV, Messier is credited with the discovery of 13 comets between 1759 and 1798. The computation of the cometary orbits, however, was left to his more mathematically sophisticated colleagues.

In 1758 he observed what appeared to be a faint comet in Taurus. Further examination revealed it to be a nebula, an immense cloud of gas. Messier thought it sensible to provide a list of such objects “so that astronomers would not confuse these same nebulae with comets just beginning to shine.” He published his first list of 45 nebulae in 1774 under the title Catalogue des nebeleuses et des amas étoiles (Catalog of Nebulae and Star Clusters). Two supplements published in 1783 and 1784 increased the number of nebulae to 103.

The nebulae listed in the catalogs were given the identifying letter M and a number; for example, the Andromeda nebula is commonly referred to as M31.