APOD
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.
A Sun Pillar
Explanation: Have you ever seen a sun pillar ? When the air is cold and the Sun is rising or setting , falling ice crystals can reflect sunlight and create an unusual column of light. Ice sometimes forms flat, stop-sign shaped crystals as it falls from high-level clouds . Air resistance causes these crystals to lie nearly flat much of the time as they flutter to the ground. Sunlight reflects off crystals that are properly aligned, creating the sun-pillar effect. In the above picture , a sun-pillar reflects light from a setting Sun.
| Date | March 13, 2001 |
|---|---|
| Credit | Credit & Copyright: Stan Richard |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



