Why is Orion Nebula bright red?

Orion Nebula, like many other star forming emission nebulae, has lots of molecular hydrogen before the stars start to form. read more

Orion Nebula, and most star forming nebulae have the largest emission at hydrogen alpha line, which is in the deep red end of the optical spectrum. This is why Orion Nebula is glowing red in many astrophotos. read more

The Orion Nebula (also known as Messier 42, M42, or NGC 1976) is a diffuse nebula situated in the Milky Way, being south of Orion's Belt in the constellation of Orion. It is one of the brightest nebulae, and is visible to the naked eye in the night sky. read more

“Saw Orion Neb. at 64´ — wow!” My optics may have been modest and my observing skills not yet honed, but I could tell that the Great Orion Nebula was a sky object different from all the rest. The 42nd entry in the popular Messier catalog of “faint fuzzies,” the Orion Nebula is admired by stargazers worldwide. read more

The pinkish-red color of nebulae, such as M42 in Orion or the Lagoon Nebula in Sagittarius, is really a combination of four different bright spectral lines of hydrogen gas. A hydrogen atom has a single proton at its center and a single electron in its outer region. read more