Subj : Daily APOD Report To : All From : Ben Ritchey Date : Tue Feb 26 2019 10:37:09 APOD: 2019 February 25 - Red Sprite Lightning over Kununurra 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 25 [2] Red Sprite Lightning over Kununurra Image Credit & Copyright: Ben Broady [3] Explanation: What are those red filaments in the sky? It is a rarely seen form of lightning confirmed only about 30 years ago: red sprites [4] . Recent research has shown that following a powerful positive cloud-to-ground lightning [5] strike, red sprites [6] may start as 100-meter balls of ionized air [7] that shoot down from about 80-km high at 10 percent the speed of light [8] and are quickly followed [9] by a group of upward streaking ionized balls. The featured image [10] , taken just over a week ago in Kununurra [11] , Western Australia [12] , captured some red sprites while shooting a time-lapse sequence of a distant lightning storm. Pictured, green trees cover the foreground, dark mountains are seen on the horizon, ominous storm clouds [13] hover over the distant land, while red sprites [14] appear in front of stars far in the distance. Red sprites [15] take only a fraction of a second to occur [16] and are best seen when powerful thunderstorm [17] s are visible from the side. Tomorrow's picture: evolving universe [18] ------------------------------------------------------------------------------- < [19] | Archive [20] | Submissions [21] | Index [22] | Search [23] | Calendar [24] | RSS [25] | Education [26] | About APOD [27] | Discuss [28] | > [29] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [30] (MTU [31] ) & Jerry Bonnell [32] (UMCP [33] ) NASA Official: Phillip Newman Specific rights apply [34] . NASA Web Privacy Policy and Important Notices [35] A service of: ASD [36] at NASA [37] / GSFC [38] & Michigan Tech. U. [39] ---------- Site notes: [1] archivepix.html [2] image/1902/RedSprites_Broady_3000.jpg [3] http://www.benbroady.com/about/ [4] http://en.wikipedia.org/wiki/Red_sprite [5] ap120723.html [6] ap120829.html [7] http://en.wikipedia.org/wiki/Ionized-air_glow [8] https://helios.gsfc.nasa.gov/qa_gp_sl.html#sol [9] https://www.youtube.com/watch?v=ATmpgZoMRM0 [10] https://www.facebook.com/BenBroady/photos/ pb.1648435622056598.-2207520000.1550870632./2336202899946530/?type=3&theater [11] https://en.wikipedia.org/wiki/Kununurra,_Western_Australia [12] https://en.wikipedia.org/wiki/Western_Australia [13] ap100821.html [14] https://astrobob.areavoices.com/2018/05/26/ how-to-see-elusive-red-sprites-on-thundery-nights/ [15] http://www.washingtonpost.com/blogs/capital-weather-gang/post/ red-sprites-blue-jets-and-elves-what-are-these-mysterious-elusive-phenomena/ 2012/09/17/33248346-007d-11e2-b260-32f4a8db9b7e_blog.html [16] ap141013.html [17] ap130505.html [18] ap190226.html [19] ap190224.html [20] archivepix.html [21] lib/apsubmit2015.html [22] lib/aptree.html [23] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [24] calendar/allyears.html [25] /apod.rss [26] lib/edlinks.html [27] lib/about_apod.html [28] http://asterisk.apod.com/discuss_apod.php?date=190225 [29] ap190226.html [30] http://www.phy.mtu.edu/faculty/Nemiroff.html [31] http://www.phy.mtu.edu/ [32] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [33] http://www.astro.umd.edu/ [34] lib/about_apod.html#srapply [35] https://www.nasa.gov/about/highlights/HP_Privacy.html [36] https://astrophysics.gsfc.nasa.gov/ [37] https://www.nasa.gov/ [38] https://www.nasa.gov/centers/goddard/ [39] http://www.mtu.edu/ --- Mystic BBS v1.12 A43 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .