by APOD Robot » Sun Feb 03, 2019 5:06 am
An Airglow Fan from Lake to Sky
Explanation: Why would the sky look like a giant fan?
Airglow. The featured intermittent
green glow appeared to rise from a lake through the arch of our
Milky Way Galaxy, as captured during 2015 next to
Bryce Canyon in
Utah, USA. The unusual
pattern was created by atmospheric
gravity waves, ripples of alternating air pressure that can grow with height as the air thins, in this case about
90 kilometers up. Unlike
auroras powered by collisions with energetic charged particles and seen at high latitudes, airglow is due to
chemiluminescence, the
production of light in a chemical reaction. More typically seen near the horizon,
airglow keeps the night sky from ever being completely dark.
[url=https://apod.nasa.gov/apod/ap190203.html] [img]https://apod.nasa.gov/apod/calendar/S_190203.jpg[/img] [size=150]An Airglow Fan from Lake to Sky[/size][/url]
[b] Explanation: [/b] Why would the sky look like a giant fan? [url=http://www.atoptics.co.uk/highsky/airglow1.htm]Airglow[/url]. The featured intermittent [url=https://www.youtube.com/watch?v=te_H0Uo6YEA]green glow[/url] appeared to rise from a lake through the arch of our [url=http://www.atlasoftheuniverse.com/galaxy.html]Milky Way Galaxy[/url], as captured during 2015 next to [url=https://www.youtube.com/watch?v=R1B-umhdy0g]Bryce Canyon[/url] in [url=https://en.wikipedia.org/wiki/Utah]Utah[/url], USA. The unusual [url=https://www.atoptics.co.uk/highsky/hgrav.htm]pattern was created by[/url] atmospheric [url=http://www.nasa.gov/multimedia/imagegallery/image_feature_484.html]gravity waves[/url], ripples of alternating air pressure that can grow with height as the air thins, in this case about [url=http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=79817]90 kilometers up[/url]. Unlike [url=https://apod.nasa.gov/apod/ap140714.html]auroras[/url] powered by collisions with energetic charged particles and seen at high latitudes, airglow is due to [url=http://www.atoptics.co.uk/highsky/airglow2.htm]chemiluminescence[/url], the [url=https://apod.nasa.gov/apod/ap130619.html]production of light[/url] in a chemical reaction. More typically seen near the horizon, [url=http://en.wikipedia.org/wiki/Airglow]airglow[/url] keeps the night sky from ever being completely dark.
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