Amateur astronomers under starry sky are gathered for a "Messier Marathon" observing competition. The Messier objects are a set of astronomical objects first listed by French astronomer Charles Messier in 1771. All of the Messier objects are visible with binoculars or small telescopes (under favorable conditions), making them popular among amateur astronomers. In early spring, astronomers sometimes gather for "Messier marathons" when all of the objects can be viewed over a single night.