Astronomy Picture of the Day
    


Aurora Over Clouds
<< Yesterday 10.09.2003 Tomorrow >>
Aurora Over Clouds
Credit & Copyright: Dominic Cantin
Explanation: Aurorae usually occur high above the clouds. The auroral glow is created when fast-moving particles ejected from the Sun impact air molecules high in the Earth's atmosphere. An oxygen molecule, for example, will glow in a green light when reacquiring an electron lost during a collision with a solar particle. The lowest part of an aurora will typically occur at 100 kilometers up, while most clouds usually exist only below about 10 kilometers. The relative heights of clouds and auroras are shown clearly in the above picture taken last month from near Quebec City, Canada. The most likely time to see an aurora is around midnight.

January
February
March
April
May
June
July
August
September
October
November
December
 < September 2003  >
Mo Tu We Th Fr Sa Su
1234567
891011121314
15161718192021
22232425262728
2930




Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
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: aurora - clouds
Publications with words: aurora - clouds
See also:
All publications on this topic >>