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Light pillars over northern Sweden

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November 12, 2014

Light pillars in northern Sweden, November 7, 2014, by Birgit Boden — View larger. | Light pillars in northern Sweden, November 7, 2014, by Birgit Bodén

plate-like_ice_crystals — Sun pillars or light pillars are formed by reflection from hexagonal plate-like ice crystals in Earth’s air. These crystals drift through the atmosphere with a horizontal orientation, gently rocking from side to side as they fall. Diagram via University of Illinois.

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!

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November 12, 2014

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Deborah Byrd

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Deborah Byrd (asteroid 3505 Byrd) helps edit EarthSky.org and is a frequent host of EarthSky videos. Deborah created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Prior to that, she had worked for the University of Texas McDonald Observatory since 1976, and created and produced their Star Date radio series. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named in her honor in 1990, a Public Service Award from the National Science Board in 2003, and the Education Prize from the American Astronomical Society in 2020. 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.