Aurora Over the Chugach Mountains
Explanation:
Auroras can make spectacular sights.
Photographed above, flowing green auroras help the
Moon illuminate the serene
Portage Lake and the snowy
Chugach Mountains near Anchorage,
Alaska,
USA.
Although
auroras might first appear to be moonlit clouds,
they only add light to the sky and do not
block background stars from view.
Called
northern lights in the northern hemisphere,
auroras are caused by
charged particles streaming out from the
Sun entering the Earth's atmosphere.
If viewed from space, auroras can be
seen to glow in
X-ray light as well.
Predictable auroras likely occur a few days after a
powerful magnetic event
has been seen on the
Sun.
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.
