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Credit & Copyright: Maciej Winiarczyk;
Music: Jolanta Galka-Kurkowska
Explanation:
Why would the sky still glow after sunset?
Besides stars and the band of our Milky Way galaxy,
the sky might glow because it contains either noctilucent clouds or aurora.
Rare individually, both are visible in the above time lapse movie taken over
Caithness,
Scotland,
UK
taken during a single night earlier this month.
First noted in 1885, many
noctilucent clouds
are known to correlate with atmospheric meteor trails, although details and
the origins of others remain a topic of research.
These meandering bright filaments of sunlight-reflecting ice crystals are the
highest clouds in the Earth's atmosphere.
The above video captures not only a variety of
noctilucent clouds,
but also how their structure varies over minutes.
Lower clouds typically appear dark or fast moving.
About halfway through the video the clouds are joined by
aurora.
At times, low clouds,
noctilucent clouds, and aurora are all visible simultaneously,
each doing their own separate dance, and once -- see if you can
find it -- even with the
Big Dipper rotating across the background.
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NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day