#air glow

A rainbow airglow! Air glows all of the time, but it is usually hard to see. A disturbance, like a storm, may cause noticeable rippling in the Earth’s atmosphere. These gravity waves are oscillations in air, just like the ripples created when a rock is thrown in calm water. Makes sense right? But where do the colors come from? The deep red glow likely originates from OH molecules excited by ultraviolet light from the Sun. The orange and green airglow is likely caused by sodium and oxygen atoms slightly higher up. A spectacular sky is visible through this airglow, with the central band of our Milky Way Galaxy running up the image center, and M31, the Andromeda Galaxy, visible near the top left.

Image Credit & Copyright: Miguel Claro (TWAN); Rollover Annotation: Judy Schmidt