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Астронет: Астрономическая картинка дня Перламутровые облака над Швецией http://variable-stars.ru/db/msg/1595808/eng |
Credit & Copyright: P-M Hedén (Clear Skies,
TWAN)
Explanation:
Vivid and lustrous,
wafting iridescent waves of color filled this mountain
and skyscape near Tanndalen, Sweden on January 3.
Known as nacreous
clouds or mother-of-pearl clouds, they are rare.
This northern winter season they have been making
unforgettable appearances at high latitudes, though.
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 after sunset and 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.