The Orion Nebula is a vast cloud of glowing gas and dust in the middle of Orion’s Sword. At roughly 1,300 light-years away, it is one of the nearest major regions of massive star formation and is bright enough to be seen with the unaided eye from a dark site as a hazy patch below Orion’s Belt.

At its heart is the Trapezium, a compact group of young, massive stars whose intense ultraviolet radiation ionizes the surrounding hydrogen and makes the nebula shine. Their winds and radiation are also excavating cavities, compressing nearby gas, and reshaping the cloud from which new stars continue to form.

Infrared and radio observations reveal hundreds of young stars and protoplanetary disks buried throughout the Orion Molecular Cloud. The famous bright core is only the illuminated face of a much larger complex that includes dark dust lanes, reflection nebulosity, and neighboring M43, making M42 one of astronomy’s most important natural laboratories for studying how stars and planetary systems are born.

The nebula lies within Orion, one of the most recognizable constellations in the sky. In Greek tradition Orion is a mighty hunter, often described as exceptionally strong and skilled, and his stories connect him with figures such as Artemis, Scorpius, and the hunting dogs represented by Canis Major and Canis Minor.

Different versions of the myth explain Orion’s death in different ways. In one tradition a scorpion kills the hunter, and the two are placed on opposite sides of the heavens: as Scorpius rises, Orion sets. The arrangement turns their story into a seasonal pursuit played out across the sky.

The fuzzy glow we call the Orion Nebula was not recognized as a nebula in antiquity, but its location is striking: it sits in the Sword hanging beneath Orion’s Belt. Long before telescopes revealed the Trapezium and the clouds of M42, cultures around the world built stories around Orion’s bright stars and distinctive hourglass-shaped figure.