M2 is, under extremely good conditions, just visible to the naked eye five degrees north of the star Beta Aquarii. Binoculars or small telescopes will identify this cluster as non-stellar while larger telescopes will resolve individual stars, of which the brightest are of apparent magnitude 13.1.

M2 was discovered by the French astronomer Jean-Dominique Maraldi in 1746 when he was observing a comet with Jacques Cassini. Charles Messier rediscovered it in 1760 and thought it a nebula without any stars associated with it. William Herschel was the first to resolve individual stars in the cluster in 1794.