Subj : Daily APOD Report To : All From : Ben Ritchey Date : Mon Sep 03 2018 08:31:13 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 September 3 [2] Aurora around Saturn's North Pole Image Credit [3] : NASA [4] , ESA [5] , Hubble [6] , OPAL Program [7] , J. DePasquale [8] (STScI [9] ), L. Lamy [10] (Obs. Paris [11] ) Explanation: Are Saturn's auroras like Earth's? To help answer this question, the Hubble Space Telescope [12] and the Cassini spacecraft [13] monitored Saturn's North Pole simultaneously during Cassini's final orbits [14] around the gas giant in September 2017. During this time, Saturn [15] 's tilt caused its North Pole to be clearly visible [16] from Earth. The featured image [17] is a composite of ultraviolet images [18] of aurora and optical images of Saturn's clouds and rings, all taken recently by Hubble. Like on Earth, Saturn's northern auroras can make total or partial rings [19] around the pole. Unlike on Earth, however, Saturn's auroras [20] are frequently spirals -- and more likely to peak in brightness just before midnight and dawn. In contrast to Jupiter's auroras [21] , Saturn's auroras [22] appear better related to connecting Saturn's internal magnetic field to the nearby, variable, solar wind [23] . Saturn's southern auroras [24] were similarly imaged back in 2004 when the planet's South Pole [25] was clearly visible to Earth. Teachers: APOD in the Classroom [26] Tomorrow's picture: moon vs volcano ------------------------------------------------------------------------------- < [27] | Archive [28] | Submissions [29] | Index [30] | Search [31] | Calendar [32] | RSS [33] | Education [34] | About APOD [35] | Discuss [36] | > [37] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [38] (MTU [39] ) & Jerry Bonnell [40] (UMCP [41] ) NASA Official: Phillip Newman Specific rights apply [42] . NASA Web Privacy Policy and Important Notices [43] A service of: ASD [44] at NASA [45] / GSFC [46] & Michigan Tech. U. [47] ---------- Site notes: [1] archivepix.html [2] image/1809/SaturnAurora_Hubble_2215.jpg [3] https://www.spacetelescope.org/copyright/ [4] https://www.nasa.gov/ [5] http://www.esa.int/ [6] https://www.nasa.gov/mission_pages/hubble/main/index.html [7] https://archive.stsci.edu/prepds/opal/ [8] http://jdepasquale.com/ [9] http://www.stsci.edu/who-we-are [10] https://www.iau.org/administration/membership/individual/16559/ [11] https://www.obspm.fr/ [12] https://www.nasa.gov/mission_pages/hubble/story/index.html [13] https://saturn.jpl.nasa.gov/mission/about-the-mission/summary/ [14] ap170125.html [15] https://solarsystem.nasa.gov/planets/saturn/overview/ [16] ap150621.html [17] https://www.spacetelescope.org/images/heic1815a/ [18] https://science.nasa.gov/ems/10_ultravioletwaves [19] ap081119.html [20] https://en.wikipedia.org/wiki/Magnetosphere_of_Saturn#Aurorae [21] ap160711.html [22] https://www.spacetelescope.org/news/heic1815/ [23] https://en.wikipedia.org/wiki/Solar_wind [24] ap050219.html [25] ap050222.html [26] https://apod.nasa.gov/apod/lib/apodclass.html [27] ap180902.html [28] archivepix.html [29] lib/apsubmit2015.html [30] lib/aptree.html [31] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [32] calendar/allyears.html [33] /apod.rss [34] lib/edlinks.html [35] lib/about_apod.html [36] http://asterisk.apod.com/discuss_apod.php?date=180903 [37] ap180904.html [38] http://www.phy.mtu.edu/faculty/Nemiroff.html [39] http://www.phy.mtu.edu/ [40] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [41] http://www.astro.umd.edu/ [42] lib/about_apod.html#srapply [43] https://www.nasa.gov/about/highlights/HP_Privacy.html [44] https://astrophysics.gsfc.nasa.gov/ [45] https://www.nasa.gov/ [46] https://www.nasa.gov/centers/goddard/ [47] http://www.mtu.edu/ --- Mystic BBS v1.12 A39 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .