{{Short description|Plain on Mars}}{{use mdy dates|date=October 2015}} {{Infobox feature on celestial object |name = Oxia Planum |image = [[File:Oxia Planum near Coogoon Vallis by HiRise.jpg|250px]] |location = [[Oxia Palus quadrangle]] |coordinates = {{coord|18.275|N|335.368|E|globe:mars_type:landmark|display=inline,title}} |type = Plains }}
'''Oxia Planum''' is a 200 km-wide clay-bearing [[plain]] located on the planet of [[Mars]] inside the [[Oxia Palus quadrangle]] on the eastern border of [[Chryse Planitia]]. The plain lies between the [[Mawrth Vallis]] [[Outflow channels|outflow channel]] to the north-east and the [[Ares Vallis]] [[Outflow channels|outflow channel]] to the south-west. In 2019, the [[International Astronomical Union]] Working Group for Planetary System Nomenclature officially approved Oxia Planum as a feature on the surface of Mars (near 18.275°N 335.368°E).<ref name=":0">{{Cite journal|last1=Quantin-Nataf|first1=Cathy|last2=Carter|first2=John|last3=Mandon|first3=Lucia|last4=Thollot|first4=Patrick|last5=Balme|first5=Matthew|last6=Volat|first6=Matthieu|last7=Pan|first7=Lu|last8=Loizeau|first8=Damien|last9=Millot|first9=Cédric|last10=Breton|first10=Sylvain|last11=Dehouck|first11=Erwin|date=2021-01-05|title=Oxia Planum: The Landing Site for the ExoMars "Rosalind Franklin" Rover Mission: Geological Context and Prelanding Interpretation|url= |journal=Astrobiology|volume=21|issue=3|pages=345–366|doi=10.1089/ast.2019.2191|issn=1531-1074|pmc=7987365|pmid=33400892}}</ref><ref>{{Cite web|title=ESA mission updates|url=https://www.planetary.org/articles/11041714-esa-mission-updates|access-date=2021-05-01|website=The Planetary Society|language=en}}</ref>
Oxia Planum was one of eight potential landing sites for the European Space Agency and Roscosmos ExoMars mission. After a five-year-long selection process, it was officially selected to be the landing site for [[Rosalind Franklin (rover)|''Rosalind Franklin'' (rover)]]. It met the rover landing criteria based on its latitude, elevation,<ref>{{Cite journal|last1=Mandon|first1=Lucia|last2=Parkes Bowen|first2=Adam|last3=Quantin-Nataf|first3=Cathy|last4=Bridges|first4=John C.|last5=Carter|first5=John|last6=Pan|first6=Lu|last7=Beck|first7=Pierre|last8=Dehouck|first8=Erwin|last9=Volat|first9=Matthieu|last10=Thomas|first10=Nicolas|last11=Cremonese|first11=Gabriele|date=2021-03-01|title=Morphological and Spectral Diversity of the Clay-Bearing Unit at the ExoMars Landing Site Oxia Planum|journal=Astrobiology|volume=21|issue=4|pages=464–480|doi=10.1089/ast.2020.2292|pmid=33646016 |issn=1531-1074|doi-access=|url=https://hal.sorbonne-universite.fr/hal-03263480/document}}</ref> surface slopes,<ref>{{Cite journal|last1=Turchinskaya|first1=O. I.|last2=Agapkin|first2=I. A.|last3=Dmitroskiy|first3=A. A.|last4=Slyuta|first4=E. N.|date=March 2021|title=Analysis of the Terrain and Surface Slopes of the Potential Landing Area of the ExoMars Spacecraft Oxia Planum|url=https://ui.adsabs.harvard.edu/abs/2021LPI....52.2442T/abstract|journal=Lunar and Planetary Science Conference|language=en|issue=2548|page=2442|bibcode=2021LPI....52.2442T }}</ref> and its [[Noachian]]-aged terrains. It was chosen because of its relatively smooth topography and its abundance of hydrated minerals.<ref name=":0" /><ref name=":1">{{Cite journal|last1=Favaro|first1=E. A.|last2=Balme|first2=M. R.|last3=Davis|first3=J. M.|last4=Grindrod|first4=P. M.|last5=Fawdon|first5=P.|last6=Barrett|first6=A. M.|last7=Lewis|first7=S. R.|date=2021|title=The Aeolian Environment of the Landing Site for the ExoMars Rosalind Franklin Rover in Oxia Planum, Mars|journal=Journal of Geophysical Research: Planets|language=en|volume=126|issue=4|article-number=2020JE006723|doi=10.1029/2020JE006723|issn=2169-9100|doi-access=free|url=https://eprints.bbk.ac.uk/id/eprint/49977/1/49977.pdf}}</ref><ref>{{Cite web|title=Oxia Planum favoured for ExoMars surface mission|url=http://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Exploration/ExoMars/Oxia_Planum_favoured_for_ExoMars_surface_mission|access-date=2021-05-01|website=www.esa.int|language=en}}</ref>
==Overview== Oxia Planum contains one of the largest exposures of clay-bearing rocks on Mars.<ref name="clay" /> The age of the region was calculated to be from ~3.6 billion years old<ref>{{Cite journal|last1=Gary‐Bicas|first1=C. E.|last2=Rogers|first2=A. D.|date=2021|title=Geologic and Thermal Characterization of Oxia Planum Using Mars Odyssey THEMIS Data|url=https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020JE006678|journal=Journal of Geophysical Research: Planets|language=en|volume=126|issue=2|article-number=e2020JE006678|doi=10.1029/2020JE006678|s2cid=234174370 |issn=2169-9100|url-access=subscription}}</ref> to ~4 billion years old.<ref name=":0" /><ref name='clay'>{{cite news |last=Durnham |first=R. |url=http://redplanet.asu.edu/?p=15954 |title=ExoMars 2018 rover heading for Oxia Planum |work=Red Planet Report |date=October 21, 2015 |access-date=October 22, 2015 }}</ref> The site is iron-magnesium rich [[clay]]s, indicating that [[Water on Mars|water once played a role]] here. The site sits in an area of valley systems with the exposed rocks exhibiting different compositions, indicating a variety of deposition and wetting environments. Dark resistant units, named for being dark-toned erosion resistant areas, are spread across the surface of the site. The formation of the dark resistant units is hypothesized to have occurred from either fluvial deposits or by volcanic activity during the [[Amazonian (Mars)|Amazonian]] period. The dark resistant units may have preserved the state of the older stratum beneath it.<ref name=":0" /><ref name=":2" />
Clay accumulation underneath the remnants of a fan or delta near the outlet of Coogoon Vallis may offer preservation for [[biosignature]]s against the planet's harsh radiation and oxidation environment.<ref name='clay'/><ref name="UdL-20140514">{{cite web |url=http://marsnext.jpl.nasa.gov/workshops/2014_05/14_Oxia_Thollot_webpage.pdf |title=Oxia Planum, landing site for Mars 2020 |last1=Thollot |first1=P. |last2=Quantin |first2=C. |date=May 14, 2014 |work=Universite de Lyon, France |access-date=October 22, 2015 }}</ref><ref name="UA-20141001">{{cite web |author=Staff |url=http://www.uahirise.org/ESP_037070_1985 |title=Possible Future Mars Landing Site in Oxia Planum - ''High Resolution Imaging Science Experiment'' |work=[[The University of Arizona]] |date=October 1, 2014 |access-date=October 21, 2015 }}</ref> {{multiple image | align = center | caption_align = center | header_align = center | width = 300 | direction = horizontal | image1 = NASA-OxiaPlanum-LocationMap-20151021.png | caption1 = Oxia Planum - Location Map. | image2 = NASA-OxiaPlanum-GeologicalContext-Morphology-20140514.jpg | caption2 = Oxia Planum - Geological Context - Morphology. }}
== Aeolian features == The [[Aeolian landform|aeolian features]] observed on Oxia Planum indicate a changing wind regime. The formation of [[Periodic Bedrock Ridges|periodic bedrock ridges]] (PBRs) is hypothesized to have occurred by exposure from erosion or by wind. The PBRs record the oldest wind period of the region and indicate a north-northeast or south-southeast wind direction. The formation of [[transverse aeolian ridges]] (TARs) occurred by wind. The TARs record a second wind period of the region and indicate a northwest or north-northwest to southeast or south-southeast wind direction. Dust devils and [[windstreak]]s from the modern wind period indicate a west-northwest to east-southeast and occasionally a north-northeast to south-southwest wind direction.<ref name=":1" /><ref name=":2">{{Cite journal|last1=Silvestro|first1=S.|last2=Pacifici|first2=A.|last3=Salese|first3=F.|last4=Vaz|first4=D. A.|last5=Neesemann|first5=A.|last6=Tirsch|first6=D.|last7=Popa|first7=C. I.|last8=Pajola|first8=M.|last9=Franzese|first9=G.|last10=Mongelluzzo|first10=G.|last11=Ruggeri|first11=A. C.|date=2021|title=Periodic Bedrock Ridges at the ExoMars 2022 Landing Site: Evidence for a Changing Wind Regime|url= |journal=Geophysical Research Letters|language=en|volume=48|issue=4|article-number=e2020GL091651|doi=10.1029/2020GL091651|issn=1944-8007|pmc=7988568|pmid=33776161}}</ref>
==See also== *[[Geography of Mars]] *[[List of plains on Mars]]
==References== {{reflist|30em}}
==External links== * [http://www.google.com/mars/#lat=-0.17578&lon=1.933591&q=Oxia Google Mars zoomable map – centered on the Oxia area] * [http://www.uahirise.org/ESP_037070_1985 High resolution images] of the Oxia Planum
{{Exomars}} {{Geography of Mars}}
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[[Category:Oxia Palus quadrangle]] [[Category:Plains on Mars]] [[Category:Extraterrestrial plateaus]]