Subj : Daily APOD Report To : All From : Ben Ritchey Date : Wed Jul 18 2018 10:18:04 APOD: 2018 July 18 - Dark Slope Streaks Split on 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 18 [2] Dark Slope Streaks Split on Mars Image Credit: HiRISE [3] , MRO [4] , LPL (U. Arizona) [5] , NASA [6] Explanation: What is creating these dark streaks on Mars? No one is sure. Candidates include dust avalanches, evaporating dry ice [7] sleds [8] , and liquid water flows. What is clear is that the streaks [9] occur through light surface dust and expose a deeper dark layer. Similar [10] streaks [11] have been photographed on Mars [12] for years and are one of the few surface features that change their appearance seasonally [13] . Particularly interesting here is that larger streaks split into smaller streaks further down the slope. The featured image [14] was taken by the HiRISE camera [15] on board the Mars-orbiting Mars Reconnaissance Orbiter [16] (MRO) several months ago. Currently, a global [17] dust [18] storm [19] is encompassing much of Mars. Tomorrow's picture: open space [20] ------------------------------------------------------------------------------- < [21] | Archive [22] | Submissions [23] | Index [24] | Search [25] | Calendar [26] | RSS [27] | Education [28] | About APOD [29] | Discuss [30] | > [31] ------------------------------------------------------------------------------- Authors & editors: Robert Nemiroff [32] (MTU [33] ) & Jerry Bonnell [34] (UMCP [35] ) NASA Official: Phillip Newman Specific rights apply [36] . NASA Web Privacy Policy and Important Notices [37] A service of: ASD [38] at NASA [39] / GSFC [40] & Michigan Tech. U. [41] ---------- Site notes: [1] archivepix.html [2] image/1807/MarsSlopeStreaks_MRO_3199.jpg [3] http://hirise.lpl.arizona.edu/ [4] http://mars.jpl.nasa.gov/mro/ [5] http://www.lpl.arizona.edu/ [6] https://www.nasa.gov/ [7] ap110926.html [8] ap130617.html [9] https://en.wikipedia.org/wiki/Dark_slope_streak [10] ap100301.html [11] ap110808.html [12] https://solarsystem.nasa.gov/planets/mars/in-depth/ [13] ap150930.html [14] https://photojournal.jpl.nasa.gov/catalog/PIA22240 [15] https://www.uahirise.org/epo/about/ [16] https://www.nasa.gov/feature/jpl/ mars-reconnaissance-orbiter-preparing-for-years-ahead [17] ap180617.html [18] ap180616.html [19] ap180623.html [20] ap180719.html [21] ap180717.html [22] archivepix.html [23] lib/apsubmit2015.html [24] lib/aptree.html [25] https://antwrp.gsfc.nasa.gov/cgi-bin/apod/apod_search [26] calendar/allyears.html [27] /apod.rss [28] lib/edlinks.html [29] lib/about_apod.html [30] http://asterisk.apod.com/discuss_apod.php?date=180718 [31] ap180719.html [32] http://www.phy.mtu.edu/faculty/Nemiroff.html [33] http://www.phy.mtu.edu/ [34] https://antwrp.gsfc.nasa.gov/htmltest/jbonnell/www/bonnell.html [35] http://www.astro.umd.edu/ [36] lib/about_apod.html#srapply [37] https://www.nasa.gov/about/highlights/HP_Privacy.html [38] https://astrophysics.gsfc.nasa.gov/ [39] https://www.nasa.gov/ [40] https://www.nasa.gov/centers/goddard/ [41] http://www.mtu.edu/ --- Mystic BBS v1.12 A39 (Windows/32) * Origin: FIDONet - The Positronium Repository (1:393/68) .