Astronomy Picture of the Day

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

2024 March 4
Numerous thin pillars of light connect a landscape filled
with snow to a star filled sky. The Big Dipper can be seen through
the colourful pillars.
Please see the explanation for more detailed information.

Light Pillars Over Inner Mongolia
Image Credit & Copyright: N. D. Liao

Explanation: What's happening across that field? Pictured here are not aurorae but nearby light pillars, a phenomenon typically much closer. In most places on Earth, a lucky viewer can see a Sun pillar, a column of light appearing to extend up from the Sun caused by flat fluttering ice-crystals reflecting sunlight from the upper atmosphere. Usually, these ice crystals evaporate before reaching the ground. During freezing temperatures, however, flat fluttering ice crystals may form near the ground in a form of light snow sometimes known as a crystal fog. These ice crystals may then reflect ground lights in columns not unlike a Sun pillar. The featured image was taken last month across the Wulan Butong Grasslands in Inner Mongolia, China.

Tomorrow's picture: star painters


< | Archive | Submissions | Index | Search | Calendar | RSS | Education | About APOD | Discuss | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Amber Straughn; Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC,
NASA Science Activation
& Michigan Tech. U.