Joe Tabb in Sonora, Kentucky caught this iridescent cloud from Sonora, Kentucky on June 23, 2016. He wrote:
I was out to take pictures of lightning and noticed this brilliant iridescent cloud over a distant thunderstorm.
Nowadays, we often hear people erroneously associate these clouds with something nefarious. Nothing could be farther from the truth; they are a natural phenomenon, associated with especially tiny ice crystals or water droplets in the air. In 1954, the Dutch astronomer M. Minnaert wrote in his classic and very beautiful book The Nature of Light and Color in the Open Air:
Iridescent clouds appear in the same direction as the sun. They can appear irregularly over the clouds in the form of colored edges, spots and bands … Our feelings at the sight of such lovely clouds are of intense delight, which is difficult to describe, but which is certain due, to no small extent, to the purity of the colors, their delicate mingling and their radiant light.
Minnaert lived at a time when accurate information from true experts was more purely accessible via the books they wrote …
Bottom line: Photo of an iridescent cloud, from Joe Tabb in Kentucky. They are a natural phenomenon, associated with especially tiny ice crystals or water droplets in the air.
Deborah Byrd created the EarthSky radio series in 1991 and EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.