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Credit & Copyright: Jean-Luc Dauvergne
(Ciel et Espace);
Explanation:
It's northern noctilucent cloud season -- perhaps a time to celebrate!
Composed of small ice crystals forming only during specific conditions in the upper
atmosphere,
noctilucent clouds may become visible at sunset during
late summer when illuminated by sunlight from below.
Noctilucent clouds are the
highest
clouds known
and now established to be polar
mesospheric clouds observed from the ground.
Although observed with NASA's
AIM satellite since 2007, much about
noctilucent clouds remains unknown and so a
topic of active research.
The featured time-lapse video shows expansive and rippled
noctilucent
clouds wafting over
Paris,
France,
during a post-sunset fireworks celebration on
Bastille Day in 2009 July.
This year,
several locations
are already reporting especially
vivid displays of noctilucent clouds.
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NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: noctilucent clouds
Publications with words: noctilucent clouds
See also: