Horsehead Nebula

The “horsehead” is a dense cloud of interstellar dust and gas. Found throughout the universe, gas and dust fill the spaces between the stars. In some places they gather in great enough quantities to form a spectacular cloud, called a nebula. Dust in the horse’s “head” is so thick that it blocks light behind it. Dust and gas also make for the brilliant red color in the nebula. The blue color comes from dust that reflects the light of nearby stars.