Better known as an iridescent cloud, a cloudbow is just what it sounds like: A cloud full of rainbows.
Photographer and astronomer Oleg Bartunov captured this shot of a rare bank of iridescent clouds rising above Thamserku mountain in the Himalayas — and then was able to capture several more views just before the phenomenon dissipated.
So what causes this rare cloud sighting to occur? The mechanics behind it are not entirely dissimilar to the ones responsible for a classically-shaped rainbow. Like a rainbow, the colors are the result of sunlight interacting with the prism of water. But while a rainbow is the result of the refraction of sunlight, iridescent clouds are the result of diffraction of sunlight around very tiny water droplets inside of clouds which spiral the colors out into all directions.
You can check out some more views of the cloudbow below!
All images by permission of Oleg Bartunov.