August 19, 2013
The cosmos is full of spectacular things: ringed planets, exploding suns, rivers of stars across the night.
Noctilucent Clouds and Aurora Over Scotland
Birthday · August 19, 2013
A little universe, just for you
Your date.
Ready to give.
Free PNG · 1080 × 1350 · No account needed
Image rights and credit requirements apply when sharing or reusing imagery.
Date & occasion only
Change the year
APOD published August 19, 2013 · Video still. Full image credits are on the original APOD entry below. A publication-date match, not a photo taken on your date. Independent of NASA.
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. Follow APOD on: Facebook (Daily) (Sky) (Spanish) or Google Plus (Daily) (River)