Helio C. Vital caught these photos from Saquarema, near Rio de Janeiro, Brazil. He wrote:
These photos show the shadow cast by the anvil of a distant cumulonimbus (positioned in front of the very low sun) onto a surrounding (apparently ring-shaped) cloud a few minutes before sunset. The cloud-shaped shadow gradually covered part of the bright ring (photos 1, above, and 2, below), eventually disrupting it (photos 3 and 4, below).
Also noticed in the images are crepuscular rays and much larger cloud shadows produced on a cloud formation in the foreground.
A Canon PowerShot SX60 HS camera was used for the shots, taken at 21:07-21:11 UTC.
Thank you, Helio!
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.