Subj : Daily APOD Report To : All From : Ben Ritchey Date : Fri Aug 17 2018 08:51:38 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. 2018 August 17 [2] Perseid Fireball and Persistent Train Image Credit & Copyright [3] : Petr Horalek [4] Explanation: Before local midnight on August 12 [5] , this brilliant Perseid meteor flashed above the Poloniny Dark Sky Park, Slovakia, planet Earth. Streaking beside [6] the summer Milky Way, its initial color is likely due to the shower meteor's characteristically high speed. Moving at about 60 kilometers per second, Perseid meteors can excite green emission from oxygen atoms while passing through the thin atmosphere at high altitudes [7] . Also characteristic of bright meteors, this Perseid left a lingering visible trail known as a persistent train [8] , wafting in the upper atmosphere. Its development is followed in the inset frames, exposures separated by one minute and shown at the scale of the original image. Compared to the brief flash of the meteor, the wraith-like trail really is persistent. After an hour faint remnants of this one could still be traced, expanding to over 80 degrees on the sky. Tomorrow's picture: Seeing Titan ------------------------------------------------------------------------------- < [9] | Archive [10] | Submissions [11] | Index [12] | Search [13] | Calendar [14] | RSS [15] | Education [16] | About APOD [17] | Discuss [18] | > [19] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [20] (MTU [21] ) & Jerry Bonnell [22] (UMCP [23] ) NASA Official: Phillip Newman Specific rights apply [24] . NASA Web Privacy Policy and Important Notices [25] A service of: ASD [26] at NASA [27] / GSFC [28] & Michigan Tech. U. [29] ---------- Site notes: [1] archivepix.html [2] image/1808/2018_08_12_Bolid_Perseus_1600px.jpg [3] lib/about_apod.html#srapply [4] http://www.astronom.cz/horalek/?page_id=20 [5] http://www.astronom.cz/horalek/?p=4182 [6] https://blogs.nasa.gov/Watch_the_Skies/tag/all-sky-camera/ [7] ap140810.html [8] ap151116.html [9] ap180816.html [10] archivepix.html [11] lib/apsubmit2015.html [12] lib/aptree.html [13] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [14] calendar/allyears.html [15] /apod.rss [16] lib/edlinks.html [17] lib/about_apod.html [18] http://asterisk.apod.com/discuss_apod.php?date=180817 [19] ap180818.html [20] http://www.phy.mtu.edu/faculty/Nemiroff.html [21] http://www.phy.mtu.edu/ [22] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [23] http://www.astro.umd.edu/ [24] lib/about_apod.html#srapply [25] https://www.nasa.gov/about/highlights/HP_Privacy.html [26] https://astrophysics.gsfc.nasa.gov/ [27] https://www.nasa.gov/ [28] https://www.nasa.gov/centers/goddard/ [29] http://www.mtu.edu/ --- Mystic BBS v1.12 A39 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .