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Астронет: Астрономическая картинка дня Перламутровые облака над Лапландией http://variable-stars.ru/db/msg/1879334/eng |
Credit & Copyright: Dennis Lehtonen
Explanation:
Vivid and lustrous,
wafting iridescent waves of color wash across this skyscape
from Kilpisjцrvi, Finland.
Known as nacreous
clouds or mother-of-pearl clouds, they are rare.
But their
unforgettable
appearance was captured looking south at 69 degrees
north latitude at sunset on January 24.
A type of
polar
stratospheric cloud,
they form when unusually cold temperatures in the usually cloudless
lower
stratosphere
form ice crystals.
Still sunlit at altitudes of around 15 to 25 kilometers, the clouds can
diffract sunlight even after sunset and just before the dawn.
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.