Orion's Furnace

05h 35m 17s   −05° 23′ 15″

The Orion Nebula is the closest large stellar nursery to Earth — a vast cloud of gas and dust roughly 1,350 light-years away where new stars are being born right now. At its core, four young blue-white stars known as the Trapezium blast the surrounding hydrogen with ultraviolet radiation, causing it to fluoresce in shades of red, pink, and violet. The nebula spans about 24 light-years across and contains enough raw material to form thousands of new solar systems. Even to the naked eye it's visible as a faint smudge below Orion's belt — the middle "star" of his sword. It has been a milestone in astronomy since the 1600s: one of the first objects ever photographed through a telescope, and still one of the most studied regions of space. Within its folds, protoplanetary disks have been directly imaged — planets in the act of forming around infant stars.