Composite image of the Orion Nebula core. The Orion Nebula, also known as Messier 42 (M42), is around 1,500 light-years away and situated south of Orion's Belt in the constellation of Orion. It is the nearest region of massive star formation to Earth and is one of the brightest nebulae. The bright trapezium grouping of stars at centre represents the Orion Trapezium Cluster. It is a tight, open cluster of young stars that has formed directly out of the parent nebula and the brightest stars are in the order of 10 to 30 solar masses in size. They are within a diameter of 1.5 light years of each other and are responsible for much of the illumination of the surrounding nebula. This image is a composite of data from the Hubble Space Telescope and the European Southern Observatory's (ESO) Very Large Telescope (VLT).