{{short description|Valley in Mars}} {{Infobox feature on celestial object |name = Lethe Vallis |image = [[Image:Lethe Vallis.JPG|200px]] |caption = Lethe Vallis, as seen by [[HiRISE]]. Flow was from southwest to northeast. Wider part of Lethe Vallis had less erosive power, so mesas are left behind from pre-existing material. Scale bar is 500 meters long. |coordinates = {{coord|4|N|206.5|W|globe:mars_type:landmark|display=inline,title}} }} '''Lethe Vallis''' is a valley in the [[Elysium Planitia]] on Mars, located at 4° North and 206.5° West. It is 225 km long and is named after [[river Lethe]] in [[Katmai National Monument]], [[Alaska]], USA.<ref>{{GPN|14163|Lethe Vallis}}</ref> Lethe Vallis originates at the SE margin of the West Elysium Basin ([[Cerberus Palus]]). West Elysium Basin probably contained a lake that was 500 km across and received water from [[Athabasca Vallis]]. It was probably formed in just days or weeks and had a discharge about like the Mississippi. Some have suggested it was formed from lava flows, but lava would not be able to flow over such a low gradient for so long a distance.<ref name=Balme_2011/>
==References== <references> <ref name=Balme_2011>{{cite book |author = Balme M. R. |display-authors=et al |title = Martian Geomorphology. Geological Society, London, Special Publications, vol. 356, issue 1 |chapter = Fill and spill in Lethe Vallis: a recent flood-routing system in Elysium Planitia, Mars |journal=Geological Society, London, Special Publications |chapter-url = https://books.google.com/books?id=F_cvPNj6f5MC&q=Elysium&pg=PA203 |editor = M. R. Balme |editor2=A. S. Bargery |editor3=C. J. Gallagher |editor4=S. Gupta |publisher = MPG Books |year = 2011 |volume=356 |issue=1 |pages = 203–227 |isbn = 9781862393301 |bibcode = 2011GSLSP.356..203B |doi = 10.1144/SP356.11 |s2cid=131101019 }}</ref> </references>
{{Geography of Mars}} {{Portal bar|Solar System}}
[[Category:Valleys and canyons on Mars]] [[Category:Elysium quadrangle]]
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