Orion nebulae. Optical image of nebulae 1600 light years away in the constellation of Orion. North is at top. The Flame Nebula (NGC 2024, pink, lower centre) is bisected by a dark lane of dust. To its right is the star Altinak (Zeta Orionis), the lower left of the three stars of Orion's belt. Alnilam (Epsilon Orionis, centre right) is the middle star of Orion's belt. Directly below Altinak is the Horsehead Nebula (Barnard 33), a protrusion of dark dust over the emission nebula IC 434 (red). The red glows show the ionisation of hydrogen by radiation from nearby stars. M78 (NGC 2068, white, upper left) is a reflection nebula.