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Астронет: Астрономическая картинка дня Полярные сияния: занавес на небе http://variable-stars.ru/db/msg/eid/apod/ap960619 |
Credit & Copyright: Michael Dolan
(Michigan Tech.)
Explanation:
Looking out over
Lake Superior at dusk you see
Venus (lower left) and ...
curtains? Like an
ant
looking up at
window
curtains,
aurora
frequently appear as huge flowing light displays. These colorful,
often
spectacular phenomena are most frequently visible from locations near the
Earth's poles.
Aurora are caused by
electrons from the
solar wind
funneling to Earth along magnetic field lines,
and striking atoms and molecules in our atmosphere.
Auroral
color is determined by which atmospheric ions are struck and
recombine to form neutral atoms.
Hourly
updates of auroral sightings are posted to the WWW.
It is still controversial whether aurora make any sound audible from the
ground. If you think you have "heard an aurora,"
please report
it!
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