Астронет: Астрономическая картинка дня Гигант и ореол http://variable-stars.ru/db/msg/1198886/eng |
Credit & Copyright: Franz Kerschbaum
(Univ. Vienna)
Explanation:
On a flight from Vienna to Brussels, astronomer Franz Kerschbaum
looked out the window and
photographed this beautiful
atmospheric phenomenon,
the
glory, shining in the direction directly opposite
the Sun.
Before airplanes, the glory, known to some as the
heiligenschein or the
Specter of the Brocken, was occasionally
seen from mountaintops.
There, when conditions were right, one could
look away from the Sun
and see what appeared to be the
shadow of a giant
surrounded by a bright
halo.
Of course, the giant turns out to be the observer,
and in the modern version a silhouette of a plane
frequently occupies the glory's center.
The cause of the glory is relatively complex.
Briefly, small droplets of water
reflect,
refract, and
diffract sunlight backwards towards the Sun.
The phenomenon has a
counterpart in astronomy, where
looking out from planet Earth
in the direction opposite the Sun yields a bright spot called
the gegenschein.
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.