Subj : Daily APOD Report To : All From : Ben Ritchey Date : Sun Feb 03 2019 03:30:00 Astronomy Picture of the Day Astronomy Picture of the Day Discover the cosmos! [1] Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2019 February 3 [2] An Airglow Fan from Lake to Sky Image Credit & Copyright: Dave Lane [3] ; Rollover Annotation: Judy Schmidt [4] Explanation: Why would the sky look like a giant fan? Airglow [5] . The featured intermittent green glow [6] appeared to rise from a lake through the arch of our Milky Way Galaxy [7] , as captured during 2015 next to Bryce Canyon [8] in Utah [9] , USA. The unusual pattern was created by [10] atmospheric gravity waves [11] , ripples of alternating air pressure that can grow with height as the air thins, in this case about 90 kilometers up [12] . Unlike auroras [13] powered by collisions with energetic charged particles and seen at high latitudes, airglow is due to chemiluminescence [14] , the production of light [15] in a chemical reaction. More typically seen near the horizon, airglow [16] keeps the night sky from ever being completely dark. Follow APOD on: Instagram [17] , Facebook [18] , Reddit [19] , or Twitter [20] Tomorrow's picture: stellar superbubble ------------------------------------------------------------------------------- < [21] | Archive [22] | Submissions [23] | Index [24] | Search [25] | Calendar [26] | RSS [27] | Education [28] | About APOD [29] | Discuss [30] | > [31] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [32] (MTU [33] ) & Jerry Bonnell [34] (UMCP [35] ) NASA Official: Phillip Newman Specific rights apply [36] . NASA Web Privacy Policy and Important Notices [37] A service of: ASD [38] at NASA [39] / GSFC [40] & Michigan Tech. U. [41] ---------- Site notes: [1] archivepix.html [2] image/1601/AirglowFan_Lane_2400.jpg [3] mailto: david dot lane07 at gmail dot com [4] http://geckzilla.com/ [5] http://www.atoptics.co.uk/highsky/airglow1.htm [6] https://www.youtube.com/watch?v=te_H0Uo6YEA [7] http://www.atlasoftheuniverse.com/galaxy.html [8] https://www.youtube.com/watch?v=R1B-umhdy0g [9] https://en.wikipedia.org/wiki/Utah [10] https://www.atoptics.co.uk/highsky/hgrav.htm [11] http://www.nasa.gov/multimedia/imagegallery/image_feature_484.html [12] http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=79817 [13] ap140714.html [14] http://www.atoptics.co.uk/highsky/airglow2.htm [15] ap130619.html [16] http://en.wikipedia.org/wiki/Airglow [17] https://www.instagram.com/astronomypicturesdaily/ [18] https://www.facebook.com/AstronomyPictureOfTheDay [19] https://www.reddit.com/r/apod [20] http://twitter.com/apod/ [21] ap190202.html [22] archivepix.html [23] lib/apsubmit2015.html [24] lib/aptree.html [25] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [26] calendar/allyears.html [27] /apod.rss [28] lib/edlinks.html [29] lib/about_apod.html [30] http://asterisk.apod.com/discuss_apod.php?date=190203 [31] ap190204.html [32] http://www.phy.mtu.edu/faculty/Nemiroff.html [33] http://www.phy.mtu.edu/ [34] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [35] http://www.astro.umd.edu/ [36] lib/about_apod.html#srapply [37] https://www.nasa.gov/about/highlights/HP_Privacy.html [38] https://astrophysics.gsfc.nasa.gov/ [39] https://www.nasa.gov/ [40] https://www.nasa.gov/centers/goddard/ [41] http://www.mtu.edu/ --- Mystic BBS v1.12 A42 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .