|
Credit & Copyright: Doug Wilson
Explanation:
Have you ever seen a halo around the Sun?
This fairly common sight occurs when high thin clouds containing millions of tiny
ice crystals cover much of the sky.
Each
ice crystal acts like a miniature lens.
Because
most of the crystals have a similar
elongated hexagonal shape, light entering one crystal face and exiting
through the opposing face refracts 22
degrees,
which corresponds to the radius of the Sun Halo.
A similar Moon Halo
may be visible during the night.
The picture was taken in Gunlock,
Utah,
USA.
A flock of birds was caught by chance in the foreground.
Exactly how
ice-crystals form in clouds remains under
investigation.
Lecture: APOD editor to give public talk in Princeton tonight (April 11)
|
January February March April May June July August September October November December |
| ||||||||||||||||||||||||||||||||||||||||||||||||
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: Sun halo
Publications with words: Sun halo
See also: