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.
Crepuscular Rays Over Utah
Explanation: What could cause such rays of dark? Dark sky rays were caught in spectacular fashion earlier this month above Kanab, Utah , USA . The cause is something surprisingly familiar: shadows . Clouds near the horizon can block sunlight from reflecting off air, making columns outward from the Sun appear unusually dark . Cloud shadow s can be thought of as the complement of the more commonly highlighted crepuscular rays , also visible above, where sunlight pours though cloud holes. Sometimes, on the opposite side of the sky, anticrepuscular rays can also be seen.
| Date | August 31, 2005 |
|---|---|
| Credit | Credit & Copyright: Jean Nesheim |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



