Media Information
 
 
 
Collection:
NASA Astronomy Picture of the Day Collection
Title:
The Secret of the Black Aurora
Explanation:
What causes black aurora? These gaps in normal bright aurora [ http://www.geo.mtu.…] are frequently recorded but rarely questioned. Recent research [ http://sci.esa.int/…] using data from four Cluster spacecraft [ http://sci.esa.int/…] orbiting the Earth has now likely found the secret: black auroras [ http://www.phys.uca…] are actually anti-auroras. In normal auroras [ http://antwrp.gsfc.…], electrons [ http://www-istp.gsf…] and/or predominantly negatively charged particles fall toward Earth along surfaces of constant magnetic field [ http://www-istp.gsf…]. They ionize [ http://www-istp.gsf…] the Earth's atmosphere [ http://liftoff.msfc…] on impact, causing the bright glows. In black anti-auroras, however, negatively charged particles are sucked out from the Earth's ionosphere [ http://server5550.i…] along adjoining magnetic field [ http://www-istp.gsf…] lines. These dark anti-auroras [ http://www.gi.alask…] can climb to over 20,000 kilometers and last for several minutes. Pictured above [ http://www.geo.mtu.…], a black aurora is seen dividing bright auroras over Fairbanks, Alaska [ http://www.state.ak…], USA [ http://www.cia.gov/…].
Credit and Copyright:
Jan Curtis [ http://climate.gi.a…]
keyword:
aurora
keyword:
black aurora
keyword:
anti-aurora
facet_where:
Alaska
facet_where:
Goddard Space Flight Center (GSFC)
facet_where:
Marshall Space Flight Center (MSFC)
facet_what:
Earth
facet_what:
Aurora
original url:
http://antwrp.gsfc.…
UID:
SPD-APOD-ap020101

The Secret of the Black Aurora
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