View source for Columbia Hills (Mars)

{{short description|Range of low hills inside Gusev crater on Mars}}
{{about|the hills on Mars|the hills in Washington State, United States|Columbia Hills (Washington)}}
[[Image:Columbia Hills from MER-A landing site PIA05200 br2.jpg|thumb|right|300px|The view of Columbia Hills from the ''[[Spirit rover|Spirit]]'' landing site]]
The '''Columbia Hills''' are a range of low hills inside [[Gusev (Mars crater)|Gusev crater]] on [[Mars]]. They were observed by the [[Mars Exploration Rover]] ''[[Spirit (rover)|Spirit]]'' when it landed within the crater in 2004. They were promptly given an unofficial name by [[NASA]] since they were the most striking nearby feature on the surface. The hills lie approximately {{convert|3|km|mi}} away from the rover's original landing position. The range is named to memorialize the [[Space Shuttle Columbia disaster|Space Shuttle ''Columbia'' disaster]]. On February 2, 2004, the individual peaks of the Columbia Hills were named after the seven [[Astronaut|astronauts]] who died in the disaster. ''Spirit'' spent a few years exploring the Columbia Hills until it ceased to function in 2010. It was also considered a potential landing site for the [[Mars 2020]] [[Perseverance (rover)|''Perseverance'' rover]],<ref>{{Cite web|url=http://www.jpl.nasa.gov/news/news.php?feature=6744|title=Scientists Shortlist Three Landing Sites for Mars 2020|website=NASA/JPL|access-date=2017-02-15}}</ref> before the selection of [[Jezero (crater)|Jezero crater]] in November 2018.<ref name="NYT-20181119">{{cite news |last=Chang |first=Kenneth |title=NASA Mars 2020 Rover Gets a Landing Site: A Crater That Contained a Lake - The rover will search the Jezero Crater and delta for the chemical building blocks of life and other signs of past microbes. |url=https://www.nytimes.com/2018/11/19/science/nasa-mars-2020-rover.html |date=19 November 2018 |work=[[The New York Times]] |access-date=3 December 2018 }}</ref>

==Peaks==
The seven peaks are, from north to south:
* [[Anderson Hill (Mars)|Anderson Hill]] - named after [[Michael P. Anderson]]
* [[Brown Hill (Mars)|Brown Hill]] - named after [[David M. Brown]]
* [[Chawla Hill]] - named after [[Kalpana Chawla]]
* [[Clark Hill (Mars)|Clark Hill]] - named after [[Laurel Clark]]
* [[Husband Hill]] - named after [[Rick Husband]]
* [[McCool Hill]] - named after [[William C. McCool]]
* [[Ramon Hill]] - named after [[Ilan Ramon]]

==Rocks and Minerals of Columbia Hills==
[[Image:ColumbiaHillsUnlabelled.jpg|thumb|250px|left|Unlabelled overhead view of the Columbia Hills. A labelled version is available [[:Image:ColumbiaHillsLabelled.jpg|here]].]]
With the ''Spirit'' rover, scientists found a variety of rock types in the Columbia Hills, and they placed them into six different categories, each named after a prominent rock in the respective group: Clovis, Wishbone, Peace, Watchtower, Backstay, and Independence.  Their chemical compositions, as measured by APXS, are significantly different from each other.<ref>Squyres, S., et al.  2006  Rocks of the Columbia Hills.  J. Geophys. Res. Planets. 111, [[Digital object identifier|doi]]:[https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2005JE002562 10.1029/2005JE002562]</ref>  Most importantly, all of the rocks in Columbia Hills show various degrees of alteration by aqueous fluids.<ref>Ming, D., et al.   2006  Geochemical and mineralogical indicators for aqueous processes in the Columbia Hills of Gusev crater, Mars. J. Geophys: Res.111, [[Digital object identifier|doi]]:[https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2005JE002560 10.1029/2005JE002560]</ref>
They are enriched in the elements [[phosphorus]], [[sulfur]], [[chlorine]], and [[bromine]]—all of which can be carried around in water solutions.  The Columbia Hills’ rocks contain basaltic glass, along with varying amounts of [[olivine]] and [[sulfate]]s.<ref>Schroder, C., et al. (2005) European Geosciences Union, General Assembly, Geophysical Research abstr., Vol. 7, 10254, 2005</ref><ref>Christensen, P.R. (2005) Mineral Composition and Abundance of the Rocks and Soils at Gusev and Meridiani from the Mars Exploration Rover Mini-TES Instruments AGU Joint Assembly, 23–27 May 2005 http://www.agu.org/meetings/sm05/waissm05.html {{Webarchive|url=https://web.archive.org/web/20130513050221/http://www.agu.org/meetings/sm05/waissm05.html |date=2013-05-13 }}</ref>
The olivine abundance varies inversely with the amount of sulfates.  This is exactly what is expected because water destroys olivine but helps to produce sulfates.

Acid fog is believed to have changed some of the Watchtower rocks.  This was in a 200 meter long section of Cumberland Ridge and the Husband Hill summit.  Certain places became less crystalline and more amorphous.  Acidic water vapor from volcanoes  dissolved some minerals forming a gel.  When water evaporated a cement formed and produced small bumps.  This type of process has been observed in the lab when basalt rocks are exposed to sulfuric and [[hydrochloric acid]]s.<ref>{{Cite web|url=http://spaceref.com/mars/signs-of-acid-fog-found-on-mars.html|archive-url=https://archive.today/20160829165245/http://spaceref.com/mars/signs-of-acid-fog-found-on-mars.html|url-status=dead|archive-date=August 29, 2016|title=Signs of Acid Fog Found on Mars - SpaceRef|date=2 November 2015}}</ref><ref>{{Cite web|url=https://gsa.confex.com/gsa/2015AM/webprogram/Paper266774.html|title = Abstract: IN-SITU EVIDENCE FOR ALTERATION BY ACID FOG ON HUSBAND HILL, GUSEV CRATER, MARS (2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015))}}</ref><ref>COLE, Shoshanna B., et al.  2015. IN-SITU EVIDENCE FOR ALTERATION BY ACID FOG ON HUSBAND HILL, GUSEV CRATER, MARS.   2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015)
Paper No. 94-10</ref>

The Clovis group is especially interesting because the [[Mössbauer spectrometer]] (MB) detected [[goethite]] in it.<ref>Klingelhofer, G., et al. (2005) Lunar Planet. Sci. XXXVI abstr. 2349</ref> Goethite forms only in the presence of [[Water on Mars|water]], so its discovery is the first direct evidence of past water in the Columbia Hills's rocks. In addition, the MB spectra of rocks and outcrops displayed a strong decline in olivine presence,<ref>Schroder, C., et al. (2005) European Geosciences Union, General Assembly, Geophysical Research abstr., Vol. 7, 10254, 2005</ref> although the rocks probably once contained much olivine.<ref>Morris, S., et al.  Mossbauer mineralogy of rock, soil, and dust at Gusev crater, Mars:  ''Spirit''{{’}}s journal through weakly altered olivine basalt on the plains and pervasively altered basalt in the Columbia Hills.  J. Geophys. Res.: 111</ref>  Olivine is a marker for the lack of water because it easily decomposes in the presence of water.  Sulfate was found, and it needs water to form.

Wishstone contained a great deal of [[plagioclase]], some [[olivine]], and [[anhydrite]] (a calcium sulfate).  Peace rocks showed [[sulfur]] and strong evidence for bound water, so hydrated sulfates are suspected.  Watchtower class rocks lack olivine, implying that they may have been altered by water.  The Independence class showed some signs of [[clay]] (perhaps [[montmorillonite]], a member of the [[smectite]] group).  Clays require fairly long term exposure to water to form.

One type of soil, called Paso Robles, from the Columbia Hills, may be an evaporate deposit because it contains large amounts of sulfur, [[phosphorus]], [[calcium]], and [[iron]].<ref>Ming, D., et al.   2006  Geochemical and mineralogical indicators for aqueous processes in the Columbia Hills of Gusev crater, Mars. J. Geophys. Res.111</ref>
Also, MB found that much of the iron in Paso Robles soil was of the oxidized, Fe<sup>+++</sup> form, which would happen if water had been present.<ref>Bell, J (ed.)  The Martian Surface.  2008.  Cambridge University Press. {{ISBN|978-0-521-86698-9}}</ref>

Towards the middle of the six-year mission (a mission that was supposed to last only 90 days), large amounts of pure [[silica]] were found in the soil.  The silica could have come from the interaction of soil with acid vapors produced by volcanic activity in the presence of water or from water in a hot spring environment.<ref>{{Cite web|url=http://www.nasa.gov/mission_pages/mer/mer-20070521.html|title=NASA - Mars Rover Spirit Unearths Surprise Evidence of Wetter Past|access-date=2012-01-16|archive-date=2013-03-08|archive-url=https://web.archive.org/web/20130308054606/http://www.nasa.gov/mission_pages/mer/mer-20070521.html|url-status=dead}}</ref>

After ''Spirit'' stopped working scientists studied old data from the Miniature Thermal Emission Spectrometer ([[Mini-TES]]) and confirmed the presence of large amounts of [[carbonate]]-rich rocks, which means that regions of the planet may have once harbored water.  The carbonates were discovered in an outcrop of rocks called "Comanche."<ref>{{Cite web|url=https://www.sciencedaily.com/releases/2010/06/100603140959.htm|title = Outcrop of long-sought rare rock on Mars found}}</ref><ref>
Richard V. Morris, Steven W. Ruff, Ralf Gellert, Douglas W. Ming, Raymond E. Arvidson, Benton C. Clark, D. C. Golden, Kirsten Siebach, Göstar Klingelhöfer, Christian Schröder, Iris Fleischer, Albert S. Yen, Steven W. Squyres. Identification of Carbonate-Rich Outcrops on Mars by the Spirit Rover. ''Science'', June 3, 2010 {{doi|10.1126/science.1189667}}</ref>

==See also==
* [[Apollo 1 Hills]]
* [[Geography of Mars]]
* [[Composition of Mars]]
* [[Aeolis quadrangle]]

== References ==
{{reflist}}

==External links==
{{Commons category}}
* [https://www.google.com/mars/#lat=-14.6&lon=175.5&zoom=12&map=infrared Google Mars] [[infrared]] view of the Columbia Hills
* [http://marsrovers.jpl.nasa.gov/ Official Mars Rovers site]
* [http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20060911b/everest_iff_cypsu_A71_brt_byte-qtvr.mov Everest panorama] {{Webarchive|url=https://web.archive.org/web/20061021001346/http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20060911b/everest_iff_cypsu_A71_brt_byte-qtvr.mov |date=2006-10-21 }} - anaglyph view from the top of Husband Hill. For a better view open this URL in [[QuickTime Player]] and then maximize the player. Red-blue glasses required.

{{Mars 2020}}
{{Geography of Mars|topography}}
{{Space Shuttle Columbia}}

[[Category:Hills on Mars]]
[[Category:Mars 2020]]
[[Category:Kalpana Chawla]]
[[Category:Space Shuttle Columbia disaster]]
[[Category:Aeolis quadrangle]]