The Orion Molecular Cloud Complex (also often referred to as simply the Orion Complex) refers to a large nebula located in the constellation of Orion. The cloud itself is between 1,500 and 1,600 light-years away and is hundreds of light-years across. Several parts of the nebula can be observed through binoculars and small telescopes, with some parts (such as the Orion Nebula) being visible to the naked eye.
The nebula is important because of the sheer size as it spreads several degrees from Orion's Belt to his sword. It is also one of the most active regions of stellar formation that can be seen in the night sky, and is home to both protoplanetary discs and very young stars. The nebula is also very bright in the infrared wavelengths due to the heat-intensive processes involved in the stellar formation, although the complex contains dark nebulae, emission nebula, reflection nebula, and HII regions.