Subj : Daily APOD Report To : All From : Ben Ritchey Date : Tue Sep 18 2018 07:09:57 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 18 Salt, Pepper, and Ice Video Credit & Copyright: Maroun Habib (Moophz [2] ) Explanation: There's a "camera" comet now moving across the sky. Just a bit too dim to see with the unaided eye, Comet 21P / Giacobini-Zinner [3] has developed a long tail [4] that makes it a good sight for binoculars and sensitive cameras. The movement of the Comet 21P [5] on the sky was captured last week in the featured time-lapse video [6] compressing 90 minutes into about 2.5 seconds. What might seem odd is that the 21P's tail [7] is not following the comet's movement. This is because comet tails [8] always point away from the Sun, and the comet [9] was not moving toward the Sun [10] during the period photographed. Visible far in the background on the upper left is the Salt & Pepper star cluster, M37 [11] , while the bright red star V440 Auriga [12] is visible just about the frame's center. This 2-km ball of dust-shedding ice [13] passed its nearest to the Sun and Earth only last week and is now fading as it crosses into southern skies [14] . Comet 21P should remain visible, however, and photogenic to stabilized cameras [15] , for another month or so. Tomorrow's picture: a rose for a swan ------------------------------------------------------------------------------- < [16] | Archive [17] | Submissions [18] | Index [19] | Search [20] | Calendar [21] | RSS [22] | Education [23] | About APOD [24] | Discuss [25] | > [26] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [27] (MTU [28] ) & Jerry Bonnell [29] (UMCP [30] ) NASA Official: Phillip Newman Specific rights apply [31] . NASA Web Privacy Policy and Important Notices [32] A service of: ASD [33] at NASA [34] / GSFC [35] & Michigan Tech. U. [36] ---------- Site notes: [1] archivepix.html [2] https://moophz.com/photography [3] https://en.wikipedia.org/wiki/21P/Giacobini%E2%80%93Zinner [4] ap180913.html [5] https://www.skyandtelescope.com/observing/ comet-21p-giacobini-zinner-shines-in-september/ [6] https://www.youtube.com/watch?v=R60m1W7t1og [7] ap180823.html [8] https://spaceplace.nasa.gov/review/tails-of-wonder/ [9] http://www.calsky.com/?Comets=&sec=3&step=1&number=21P [10] https://solarsystem.nasa.gov/solar-system/sun/by-the-numbers/ [11] https://en.wikipedia.org/wiki/Messier_37 [12] https://www.universeguide.com/star/v440aurigae [13] https://www.csmonitor.com/Science/2015/0126/ What-is-comet-dust-made-of-Rosetta-finds-out [14] https://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=21P [15] ap120508.html [16] ap180917.html [17] archivepix.html [18] lib/apsubmit2015.html [19] lib/aptree.html [20] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [21] calendar/allyears.html [22] /apod.rss [23] lib/edlinks.html [24] lib/about_apod.html [25] http://asterisk.apod.com/discuss_apod.php?date=180918 [26] ap180919.html [27] http://www.phy.mtu.edu/faculty/Nemiroff.html [28] http://www.phy.mtu.edu/ [29] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [30] http://www.astro.umd.edu/ [31] lib/about_apod.html#srapply [32] https://www.nasa.gov/about/highlights/HP_Privacy.html [33] https://astrophysics.gsfc.nasa.gov/ [34] https://www.nasa.gov/ [35] https://www.nasa.gov/centers/goddard/ [36] http://www.mtu.edu/ --- Mystic BBS v1.12 A39 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .