M42, the Orion Nebula is the brightest diffuse nebula in the sky, easily visible to the naked eye, and stunning in telescopes of every size. Because of its beauty and brightness, M42 is sometimes referred to as "the Great Nebula in Orion". It covers a region in the night sky four times the area of the full Moon.
M42 is full of interesting structures and objects. Chief among these is the Trapezium Cluster, a cluster of four stars located in the heart of the nebula. M42 was first documented by the French astronomer and lawyer, Nicholas-Claude Fabri de Peiresc, in 1610.