APOD 2.1: Iridescent Cloud Edge Over Colorado

 

When watching the eclipse on October 23, spotters in Colorado suffered from cloud coverage. Unexpectadely, the clouds tarted to show iridescence, the diffraction of sunlight around a thin screen of nearly uniformly-sized water droplets. Different colors of the sunlight become deflected by different angles and come to the observer from slightly different directions. The white streak on the right are the trails of an airplane.