Subj : Daily APOD Report To : All From : Ben Ritchey Date : Sun Apr 21 2019 12:12:23 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 April 21 [2] Spiral Aurora over Icelandic Divide Image Credit & Copyright: Juan Carlos Casado [3] (TWAN [4] , StarryEarth [5] ) Explanation: Admire the beauty but fear the beast. The beauty is the aurora overhead [6] , here taking the form of great green spiral [7] , seen between picturesque clouds with the bright Moon to the side and stars in the background. The beast is the wave of charged particles that creates the aurora [8] but might, one day, impair civilization. In 1859, following notable auroras seen all across the globe, a pulse of charged particles from a coronal mass ejection [9] (CME) associated with a solar flare [10] impacted Earth's magnetosphere [11] so forcefully that they created the Carrington Event [12] . A relatively direct path between the Sun and the Earth might have been cleared by a preceding CME [13] . What is sure is that the Carrington Event compressed the Earth's magnetic field [14] so violently that currents were created [15] in telegraph wires so great that many wires sparked and gave telegraph [16] operators shocks. Were a Carrington-class [17] event to impact the Earth today, speculation holds that damage might occur [18] to global power grids and electronics on a scale never yet experienced. The featured aurora was imaged in 2016 over Thingvallavatn [19] Lake in Iceland [20] , a lake that partly fills a fault that divides [21] Earth's large Eurasian and North American tectonic plates [22] . 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[63] ---------- Site notes: [1] archivepix.html [2] image/1904/AuroraPingvllir_Casado_1336.jpg [3] http://www.twanight.org/casado [4] http://www.twanight.org [5] http://starryearth.com/ [6] ap120430.html [7] https://originalbeauty.wordpress.com/2009/06/27/spirals-in-nature/ [8] ap960527.html [9] http://solarscience.msfc.nasa.gov/CMEs.shtml [10] ap031029.html [11] https://science.nasa.gov/heliophysics/focus-areas/magnetosphere-ionosphere [12] https://en.wikipedia.org/wiki/Solar_storm_of_1859 [13] ap160110.html [14] http://www.nasa.gov/mission_pages/sunearth/news/gallery/ Earths-magneticfieldlines-dipole.html [15] https://en.wikipedia.org/wiki/Faraday%27s_law_of_induction [16] https://en.wikipedia.org/wiki/Telegraphy#Electrical_telegraphs [17] http://science.nasa.gov/science-news/science-at-nasa/2014/02may_superstorm/ [18] http://news.nationalgeographic.com/news/2011/03/ 110302-solar-flares-sun-storms-earth-danger-carrington-event-science/ [19] https://en.wikipedia.org/wiki/%C3%9Eingvallavatn [20] https://en.wikipedia.org/wiki/Iceland [21] https://www.youtube.com/watch?v=Bhu2umi0QII [22] http://www.worldatlas.com/aatlas/infopage/tectonic.gif [23] http://www.apodar.com/ [24] http://www.apod.cat/ [25] http://www.bjp.org.cn/apod/today.html [26] http://sprite.phys.ncku.edu.tw/astrolab/mirrors/apod/ apod.html [27] http://www.apod.rs/Croatia.html [28] http://www.astro.cz/apod/ [29] http://www.apod.nl/ [30] http://www.starobserver.org/ [31] http://www.cidehom.com/apod.php [32] https://www.apod.tv/ [33] http://apod.infoastronomy.org/ [34] http://home.u05.itscom.net/apodjpn/apodj/apodj0.htm [35] http://wouldyoulike.org/apod/ [36] http://www.apod.rs/Montenegro.html [37] http://apod.pl/apod/ [38] http://www.astronet.ru/db/apod.html [39] http://www.apod.rs/ [40] http://apod.fmf.uni-lj.si/ [41] http://observatorio.info/ [42] http://astronomy.pp.ua/ [43] ap190420.html [44] archivepix.html [45] lib/apsubmit2015.html [46] lib/aptree.html [47] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [48] calendar/allyears.html [49] /apod.rss [50] lib/edlinks.html [51] lib/about_apod.html [52] http://asterisk.apod.com/discuss_apod.php?date=190421 [53] ap190422.html [54] http://www.phy.mtu.edu/faculty/Nemiroff.html [55] http://www.phy.mtu.edu/ [56] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [57] http://www.astro.umd.edu/ [58] lib/about_apod.html#srapply [59] https://www.nasa.gov/about/highlights/HP_Privacy.html [60] https://astrophysics.gsfc.nasa.gov/ [61] https://www.nasa.gov/ [62] https://www.nasa.gov/centers/goddard/ [63] http://www.mtu.edu/ --- Mystic BBS v1.12 A43 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .