{{Short description|Valles on Mars}} {{Infobox feature on celestial object |name = Kasei Valles |image = Kasei Valles topolabled.JPG |caption = Vicinity of the Northern Kasei Valles, also showing [[Bahram Vallis]] and the [[Vedra Valles]], [[Maumee Valles]], and [[Maja Valles]]. Flow was from bottom left. Map is ~{{convert|1600|km|abbr=on}} wide; the system extends south another {{convert|1200|km|abbr=on}} to [[Echus Chasma]]. |coordinates = {{coord|24.6|N|65.0|W|globe:mars_type:landmark|display=inline,title}} |naming = "Mars" in Japanese }} The '''Kasei Valles''' are a giant system of [[canyon]]s in [[Mare Acidalium quadrangle|Mare Acidalium]] and [[Lunae Palus quadrangle|Lunae Palus]] quadrangles on [[Mars]], centered at 24.6° north latitude and 65.0° west longitude. They are {{convert|1580|km|abbr=on}} long and were named for the word for "Mars" in Japanese.<ref>{{gpn|2942}}</ref> This is one of the largest [[outflow channel]] systems on Mars.

== Geography == [[File:Kasei Valles mosaic (8967740946).jpg|thumb|left|Area around the Northern Kasei Valles in [[Mars Express]] images]]

This huge system is 300 miles wide in some places. In contrast, Earth's Grand Canyon is only 18 miles wide.<ref>{{Cite web |url=http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_001640_2125 |title=HiRISE &#124; (Almost) Silent Rolling Stones in Kasei Valles |access-date=2009-03-19 |archive-url=https://web.archive.org/web/20161001224225/http://hiroc.lpl.arizona.edu/images/PSP/diafotizo.php?ID=PSP_001640_2125 |archive-date=2016-10-01 |url-status=dead }}</ref> It is one of the longest continuous [[outflow channel]] systems on Mars. The Kasei Valles system begins in [[Echus Chasma]], near [[Valles Marineris]]. It runs initially northward, then turns eastward and appears to empty into [[Chryse Planitia]], not far from where [[Viking 1]] landed. At around 20° north latitude the system splits into two channels, called Kasei Vallis Canyon and North Kasei Channel.{{citation needed|date=July 2014}} These branches recombine at around 63° west longitude, forming a large island between the channels known as [[Sacra Mensa]]. Some parts of the Kasei Valles are 2–3&nbsp;km deep.<ref>Baker, V. 1982. The Channels of Mars. University of Texas Press. Austin</ref>

Like other outflow channels, they were likely carved by liquid water, possibly released by volcanic subsurface heating in the [[Tharsis]] region, either as a one-time catastrophic event or multiple flooding events over a long time period. Others have proposed that certain landforms were produced by glacial rather than liquid flow.<ref>{{Cite web | url=http://themis.asu.edu/zoom-20050427a | title=Islands in Kasei Vallis (Released 27 April 2005) &#124; Mars Odyssey Mission THEMIS}}</ref>

Three sets of enormous cataracts (dry falls) are present in the area between an "island" feature in the southern channel, Lunae Mensae, and the crater [[Sharonov (Martian crater)|Sharonov]].<ref name = "Coleman2010">{{cite conference | first = N. | last = Coleman | title = Spectacular cataracts (dry falls) on the floor of Kasei Valles, Mars | book-title = 41st Lunar and Planetary Science Conference | pages = 1174 | publisher = [[Lunar and Planetary Institute]] | date = March 2010 | bibcode = 2010LPI....41.1174C | id = 1533 }}</ref><ref name = "Coleman2013">{{cite conference | first = N. | last = Coleman |author2=Lindberg, S. | title = New insights about cataracts (dry falls) on the floor of Kasei Valles, Mars | book-title = 44th Lunar and Planetary Science Conference | pages = 1148 | publisher = [[Lunar and Planetary Institute]] | date = March 2013 | bibcode = 2013LPI....44.1148C | id = 1719 }}</ref> These cataracts, evidently carved during megaflooding events, have headwalls up to 400 m high<ref name = "Coleman2013"/> and are considerably larger than the largest terrestrial analog, [[Dry Falls]].<ref name = "Coleman2010"/> They may have migrated over 100&nbsp;km upstream subsequent to their initial formation.<ref name = "Coleman2010"/> {{Clearleft}}

== Gallery == <gallery class="center" widths="190px" heights="180px" >

Image:Lunae Palus map.JPG|Map of [[Lunae Palus quadrangle]] with labels. The Kasei Valles can be seen at the top of the image.

File:Kasei Valles THEMIS day IR v11.5 0.4.jpg|High resolution [[Thermal Emission Imaging System|THEMIS]] daytime infrared image mosaic of the Kasei Valles and their surroundings.

Image:Kasei Valles.jpg|[[THEMIS]] image illustrating details of channels.

Image:Cliff in Mare Acidalium.JPG|Cliff in the Kasei Valles system, as seen by [[HiRISE]].

Image:Rolling boulders in kasei.JPG|Enlargement of cliff in the Kasei Valles system in previous image showing boulders and their tracks, as seen by [[HiRISE]]. The boulders are around 2 m across.

Image:Kasei Valles THEMIS flow features.jpg|View of streamlined landforms in the Kasei Valles (detail from THEMIS mosaic at left).

Image:Kasei Valles cataracts.jpg|View showing putative cataracts in the Kasei Valles southwest of [[Sharonov (Martian crater)|Sharonov]] (detail from THEMIS mosaic).

</gallery>

== References == {{reflist}}

==Further reading==

*{{cite book |author=Baker, V.R. |author2=Carr, M.H. |author3=Gulick, V.C. |author4=Williams, C.R. |author5=Marley, M.S. |name-list-style=amp |chapter=Channels and Valley Networks |title=Mars |editor=Kieffer, H.H. |editor2=Jakosky, B.M. |editor3=Snyder, C.W. |editor4=Matthews, M.S. |publisher=[[University of Arizona Press]] |location=Tucson, AZ }} *{{cite book |author=Carr, M.H. |chapter=Channels, Valleys and Gullies |title=The Surface of Mars |publisher=[[Cambridge University Press]] |isbn=978-0-521-87201-0 |date=2007-01-11 }}

==External links== {{Commonscat|Kasei Valles}} *[http://www.esa.int/esaMI/Mars_Express/SEMH916LARE_1.html Kasei Valles outflow channel system] - [[European Space Agency]] *[http://spaceinimages.esa.int/Images/2013/06/Kasei_Valles_mosaic Kasei Valles mosaic] (ESA) {{Geography of Mars}} {{Portal bar|Solar System}}

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[[Category:Mare Acidalium quadrangle]] [[Category:Lunae Palus quadrangle]] [[Category:Valleys and canyons on Mars]]