All the Colors of the Sky: Decoding Rainbows, Halos, and Coronas

What do you see when you look up?

Clues to the state of the atmosphere are all around us if we know how and where to look. The rainbow is probably one of the best known signs as its brilliant colors and dramatic appearance make it hard to miss. But there’s more to rainbows than you might guess. If a halo or rainbow is observed in the sky, it is carrying information about the shapes, sizes, and/or composition of airborne particles. Each rainbow and rainbow-esque phenomenon carries its own specific information about the particles that generate it. This information is sometimes difficult to obtain from other sources. 

The streaks of color may not last long, and they occur at unpredictable times. But in cases where the actual state of the atmosphere at a certain moment is of importance, or when one is interested in knowing the composition of particles floating in the air, their observation may help. So remember that every time you see and photograph a rainbow, you’re making important observations about the world around you.