Horsehead Nebula
Astrophotography
The Horsehead Nebula is a dark nebula in the constellation Orion, silhouetted against the bright emission nebula IC 434. It lies about 1,300‑1,400 light‑years from Earth. Its distinctive shape—the “horse head” silhouette—is caused by dense dust and molecular gas that block light, while behind it hydrogen gas glows red due to ionization from nearby hot stars (notably the sigma Orionis cluster). The nebula is part of the larger Orion Molecular Cloud Complex.