EarthSky Facebook friend Birgit Bodén shared this photo. It’s a sign of wintry weather already appearing at far northern latitudes. These streaks in the sky are called light pillars. They form when sunlight (or another bright light source, such as the sun) reflects off the surfaces of millions of falling ice crystals associated with thin, high-level clouds, for example, cirrostratus clouds. The ice crystals have roughly horizontal faces. They are falling through Earth’s atmosphere, rocking slightly from side to side.
Light pillars can be seen at any time of night when sky conditions are just right.
Thank you, Birgit!
Deborah Byrd created the EarthSky radio series in 1991 and founded 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.