APOD: 2021 December 28

Discover the universe! Each day a different image or photograph of our universe is featured, along with a brief explanation written by an astronomer.

December 28, 2021.

Sun halo over Sweden.

Hkan Hammar is the owner of the Vemdalen Ski Resort.

What has happened to the Sun? Sometimes it looks like the Sun is being viewed through a giant lens. There are millions of ice crystals in the featured video. Water may freeze in the atmosphere into ice. As these crystals flutter to the ground, a lot of time is spent with their faces parallel to the ground. An observer can see the ice crystals falling near sunrise or sunset. During this alignment, each crystal can act like a miniature lens, reflecting sunlight into our view and creating phenomena like parhelia, the technical term for sundogs. The video was taken on the side of a ski hill at the Vemdalen Ski Resort in central Sweden. The most direct image of the Sun is visible in the center, while two sundogs glow from the left and right. The bright 22 degree halo is created by the sun's rays, as well as the rarer and much fainter 46 degree halo, which is created by atmospheric ice crystals.

The picture is of giant storms.

Robert Nemiroff is an author and Jerry Bonnell is an editor.

Phillip Newman has specific rights.

NASA has a privacy policy on the internet.

There is a service at NASA.

& Michigan Tech. U.