Астронет: Астрономическая картинка дня Столб света над вулканом Этна http://variable-stars.ru/db/msg/1784675/eng |
Credit & Copyright: Giancarlo
Tinц
Explanation:
What happening above that volcano?
Something very unusual -- a volcanic
light pillar.
More typically, light pillars are caused by sunlight and so appear as a bright column
that extends upward above a rising or setting
Sun.
Alternatively, other light pillars --
some
quite
colorful -- have been recorded above street and house
lights.
This light pillar, though, was illuminated by the
red light emitted by the glowing magma of an
erupting volcano.
The volcano is
Italy's
Mount Etna, and the
featured image was
captured with a single shot a few hours after sunset in mid-June.
Freezing temperatures above the volcano's
ash cloud created
ice-crystals
either in
cirrus clouds high above the volcano --
or in condensed water vapor expelled by
Mount Etna.
These ice crystals -- mostly
flat
toward the ground but fluttering --
then reflected away light from the
volcano's caldera.
Explore Your Universe:
Random APOD Generator
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.