Subj : Daily APOD Report To : All From : Ben Ritchey Date : Sun Nov 25 2018 09:44:25 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 November 25 [2] Phobos: Doomed Moon of Mars Image Credit: Viking Project [3] , JPL [4] , NASA [5] ; Mosaic Processing: Edwin V. Bell II (NSSDC [6] / Raytheon [7] ITSS) Explanation: This moon is doomed. Mars [8] , the red planet named for the Roman god of war [9] , has two tiny moons, Phobos [10] and Deimos [11] , whose names are derived from the Greek for Fear and Panic [12] . The origin of the Martian moons is unknown, though, with a leading hypothesis holding that they are captured asteroids [13] . The larger moon, at 25-kilometers across, is Phobos [14] , and is indeed seen to be a cratered, asteroid-like object in this false-colored image [15] mosaic taken by the robotic Viking 1 mission in 1978. A recent analysis [16] of the unusual long grooves seen on Phobos [17] indicates that they may result from boulders rolling away from the giant impact that created the crater on the upper left: Stickney Crater [18] . Phobos [19] orbits so close to Mars - about 5,800 kilometers above the surface compared to 400,000 kilometers for our Moon [20] - that gravitational tidal force [21] s are dragging it down. The ultimate result will be for Phobos to break up [22] in orbit and then crash down onto the Martian surface in about 50 million years. Well before that -- tomorrow, in fact, if everything goes according to plan -- NASA's robotic InSight lander will touch down [23] on Mars and begin investigating its internal structure. Latest: Insight to Land on Mars Tomorrow [24] Tomorrow's picture: up, up, and away ------------------------------------------------------------------------------- < [25] | Archive [26] | Submissions [27] | Index [28] | Search [29] | Calendar [30] | RSS [31] | Education [32] | About APOD [33] | Discuss [34] | > [35] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [36] (MTU [37] ) & Jerry Bonnell [38] (UMCP [39] ) NASA Official: Phillip Newman Specific rights apply [40] . NASA Web Privacy Policy and Important Notices [41] A service of: ASD [42] at NASA [43] / GSFC [44] & Michigan Tech. U. [45] ---------- Site notes: [1] archivepix.html [2] image/1811/Phobos_Viking1_1175.jpg [3] https://mars.nasa.gov/programmissions/missions/past/viking/ [4] https://www.jpl.nasa.gov/ [5] https://www.nasa.gov/ [6] https://nssdc.gsfc.nasa.gov/ [7] https://www.raytheon.com/ [8] http://mars.jpl.nasa.gov/allaboutmars/extreme/ [9] https://en.wikipedia.org/wiki/Mars_(mythology) [10] https://solarsystem.nasa.gov/moons/mars-moons/phobos/in-depth/ [11] https://solarsystem.nasa.gov/moons/mars-moons/deimos/in-depth/ [12] http://1.bp.blogspot.com/-yzPdCk_Kc30/UcsbcNxTCKI/AAAAAAAAB-I/9bTfzfm9KKw/ s1600/scared_cat_is_really_scared-e1349731123898.jpg [13] https://solarsystem.nasa.gov/asteroids-comets-and-meteors/asteroids/overview/ [14] ap030329.html [15] https://nssdc.gsfc.nasa.gov/photo_gallery/caption/vik_phobos_caption.html [16] https://news.brown.edu/articles/2018/11/phobos [17] ap151122.html [18] ap180505.html [19] http://www.youtube.com/watch?v=IHDH7cKX_SA [20] ap020504.html [21] https://en.wikipedia.org/wiki/Tidal_force [22] https://en.wikipedia.org/wiki/Phobos_(moon)#Predicted_destruction [23] https://www.nasa.gov/feature/jpl/nasa-insight-landing-on-mars-milestones [24] https://twitter.com/NASAInSight [25] ap181124.html [26] archivepix.html [27] lib/apsubmit2015.html [28] lib/aptree.html [29] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [30] calendar/allyears.html [31] /apod.rss [32] lib/edlinks.html [33] lib/about_apod.html [34] http://asterisk.apod.com/discuss_apod.php?date=181125 [35] ap181126.html [36] http://www.phy.mtu.edu/faculty/Nemiroff.html [37] http://www.phy.mtu.edu/ [38] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [39] http://www.astro.umd.edu/ [40] lib/about_apod.html#srapply [41] https://www.nasa.gov/about/highlights/HP_Privacy.html [42] https://astrophysics.gsfc.nasa.gov/ [43] https://www.nasa.gov/ [44] https://www.nasa.gov/centers/goddard/ [45] http://www.mtu.edu/ --- Mystic BBS v1.12 A39 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .