Subj : Daily APOD Report To : All From : Ben Ritchey Date : Tue Jul 31 2018 10:18:03 APOD: 2018 July 31 - Layers of the South Pole of Mars 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 July 31 [2] Layers of the South Pole of Mars Image Credit & License [3] : ESA [4] / DLR [5] / FU Berlin [6] ; Bill Dunford [7] Explanation: What lies beneath the layered south pole of Mars? A recent measurement [8] with ground-penetrating radar [9] from ESA's Mars Express satellite [10] has detected a bright reflection layer consistent with [11] an underground lake of salty water [12] . The reflection [13] comes from about 1.5-km down but covers an area 200-km across. Liquid water evaporates quickly from the surface of Mars [14] , but a briny confined lake [15] , such as implied by the radar reflection, could last much longer and be a candidate to host life such as microbes [16] . Pictured [17] , an infrared [18] , green, and blue image [19] of the south pole of Mars taken by Mars Express in 2012 shows a complex mixture of layers [20] of dirt, frozen carbon dioxide [21] , and frozen water [22] . Tomorrow's picture: intersteallar iris [23] ------------------------------------------------------------------------------- < [24] | Archive [25] | Submissions [26] | Index [27] | Search [28] | Calendar [29] | RSS [30] | Education [31] | About APOD [32] | Discuss [33] | > [34] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [35] (MTU [36] ) & Jerry Bonnell [37] (UMCP [38] ) NASA Official: Phillip Newman Specific rights apply [39] . NASA Web Privacy Policy and Important Notices [40] A service of: ASD [41] at NASA [42] / GSFC [43] & Michigan Tech. U. [44] ---------- Site notes: [1] archivepix.html [2] image/1807/SouthPole_MarsExpress_2310.jpg [3] https://www.esa.int/spaceinimages/ESA_Multimedia/Copyright_Notice_Images [4] http://www.esa.int/ [5] http://www.dlr.de/pf/ [6] http://www.fu-berlin.de/ [7] http://www.planetary.org/connect/our-experts/profiles/bill-dunford.html [8] http://www.esa.int/Our_Activities/Space_Science/Mars_Express/ Mars_Express_detects_liquid_water_hidden_under_planet_s_south_pole [9] https://en.wikipedia.org/wiki/Ground-penetrating_radar [10] http://sci.esa.int/mars-express/ [11] http://science.sciencemag.org/content/early/2018/07/24/science.aar7268 [12] https://www.youtube.com/watch?v=0CHJW9oFZhg [13] http://sci.esa.int/mars-express/ 60518-mars-express-detects-water-buried-under-the-south-pole-of-mars/ [14] https://solarsystem.nasa.gov/planets/mars/overview/ [15] ap040404.html [16] ap090830.html [17] http://www.planetary.org/multimedia/space-images/mars/ 20130810_mars_polar_mex_jul13.html [18] https://science.nasa.gov/ems/07_infraredwaves [19] https://www.esa.int/spaceinimages/Images/2015/02/ Cappuccino_swirls_at_Mars_south_pole [20] ap171219.html [21] https://www.youtube.com/watch?v=sSV5yGgU85I [22] ap050720.html [23] ap180801.html [24] ap180730.html [25] archivepix.html [26] lib/apsubmit2015.html [27] lib/aptree.html [28] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [29] calendar/allyears.html [30] /apod.rss [31] lib/edlinks.html [32] lib/about_apod.html [33] http://asterisk.apod.com/discuss_apod.php?date=180731 [34] ap180801.html [35] http://www.phy.mtu.edu/faculty/Nemiroff.html [36] http://www.phy.mtu.edu/ [37] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [38] http://www.astro.umd.edu/ [39] lib/about_apod.html#srapply [40] https://www.nasa.gov/about/highlights/HP_Privacy.html [41] https://astrophysics.gsfc.nasa.gov/ [42] https://www.nasa.gov/ [43] https://www.nasa.gov/centers/goddard/ [44] http://www.mtu.edu/ --- Mystic BBS v1.12 A39 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .