Elysium Planitia

{{Use dmy dates|date=December 2022}} {{Short description|Broad plain that straddles the equator of Mars}} {{about|the plain on Mars|other uses|Elysium (disambiguation)}} {{Infobox feature on celestial object |name = Elysium Planitia |image = [[Image:Elysium Planitia topo.jpg|center||280px|frameless]] |caption = [[Mars Orbiter Laser Altimeter (MOLA)|MOLA]] topographical map of Elysium Planitia (spacecraft landing sites are annotated in [[c:File:Elysium Planitia topo.jpg|Commons]]) |coordinates = {{coord|3.0|N|154.7|E|globe:mars_type:landmark|display=inline,title}} }} [[File:Elysium Planitia labelled view.jpg|thumb|Location of Elysium Plantia on Mars]]

'''Elysium Planitia''', located in the [[Elysium quadrangle|Elysium]] and [[Aeolis quadrangle|Aeolis]] quadrangles, is a broad plain that straddles the equator of [[Mars]], centered at {{Coord|3.0|154.7|globe:Mars}}.<ref name = "USGS">{{cite web | title = Elysium Planitia | work = Gazetteer of Planetary Nomenclature | publisher = [[USGS Astrogeology Science Center]] | url = https://planetarynames.wr.usgs.gov/Feature/1784 | access-date = 7 May 2018}}</ref> It lies to the south of the volcanic province of [[Elysium (volcanic province)|Elysium]], the second largest [[volcano|volcanic]] region on the planet, after [[Tharsis]]. Elysium contains the major volcanoes [[Elysium Mons]], [[Albor Tholus]] and [[Hecates Tholus]]. Another more ancient [[shield volcano]], [[Apollinaris Mons]], is situated just to the south of eastern Elysium Planitia. Within the plains, [[Cerberus Fossae]] is the only Mars location with recent volcanic eruptions. Lava flows dated no older than 0.2 million years from the present have been found,<ref>{{citation|arxiv=2011.05956|title=Evidence for geologically recent explosive volcanism in Elysium Planitia, Mars|year=2021|last1=Horvath|first1=David G.|last2=Moitra|first2=Pranabendu|last3=Hamilton|first3=Christopher W.|last4=Craddock|first4=Robert A.|last5=Andrews-Hanna|first5=Jeffrey C.|journal=Icarus|volume=365|article-number=114499|doi=10.1016/j.icarus.2021.114499|bibcode=2021Icar..36514499H|s2cid=226299879}}</ref> and evidence has been found that [[Volcanism on Mars|volcanic activity]] may have occurred as recently as 53,000 years ago. Such activity could have provided the environment, in terms of energy and chemicals, needed to support [[life form]]s.<ref name="NYT-20201120">{{cite news |last=O'Callaghan |first=Jonathan |title=Signs of Recent Volcanic Eruption on Mars Hint at Habitats for Life - Not thought to be volcanically active, Mars may have experienced an eruption just 53,000 years ago. |url=https://www.nytimes.com/2020/11/20/science/mars-volcano-eruption.html |date=20 November 2020 |work=[[The New York Times]] |access-date=25 November 2020 }}</ref><ref name="ARX-20201111">{{cite journal |author=Horvath, David G. |display-authors=et al. |title=Evidence for geologically recent explosive volcanism in Elysium Planitia, Mars |journal=Icarus |year=2021 |volume=365 |article-number=114499 |doi=10.1016/j.icarus.2021.114499 |arxiv=2011.05956 |bibcode=2021Icar..36514499H |s2cid=226299879 }}</ref>

The largest craters in Elysium Planitia are [[Eddie (crater)|Eddie]], [[Lockyer (Martian crater)|Lockyer]], and [[Tombaugh (Martian crater)|Tombaugh]]. The planitia also has river valleys—one of which, [[Athabasca Valles]] may be one of the youngest on Mars. On the north east side is an elongated depression called [[Orcus Patera]], and this and some of the eastern plains were imaged in the 1965 [[Mariner 4]] flyby.<ref>{{cite web|last1=Williams|first1=Dave|last2=Friedlander|first2=Jay|title=The Orcus Patera region on Mars|url=http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/m04_03b.html|website=Mars - Mariner 4|publisher=[[NASA]]|access-date=20 December 2015|archive-date=10 April 2022|archive-url=https://web.archive.org/web/20220410030536/https://nssdc.gsfc.nasa.gov/imgcat/html/object_page/m04_03b.html|url-status=dead}}</ref>

A 2005 photo of a locale in Elysium Planitia at 5°N, 150°E by the [[Mars Express]] spacecraft shows what may be ash-covered water ice. The volume of ice is estimated to be {{convert|800|km|mi|abbr=on}} by {{convert|900|km|mi|abbr=on}} in size and {{convert|45|m|ft|abbr=on}} deep, similar in size and depth to the [[North Sea]].<ref>{{cite news| url=https://www.newscientist.com/article.ns?id=dn7039| title='Pack ice' suggests frozen sea on Mars| publisher=New Scientist| date=25 February 2005| first=Kelly| last=Young| access-date=30 January 2007| archive-date=9 February 2007| archive-url=https://web.archive.org/web/20070209043952/http://www.newscientist.com/article.ns?id=dn7039}}</ref> The ice is thought to be the remains of water floods from the [[Cerberus Fossae]] fissures about 2 to 10 million years ago. The surface of the area is broken into 'plates' like broken ice floating on a lake (see [[#Gallery|below]]). Impact crater counts show that the plates are up to 1 million years older than the gap material, showing that the area solidified much too slowly for the material to be basaltic lava.<ref>{{cite journal | title = Evidence ... for a frozen sea close to Mars' equator | journal = Nature | volume = 434 | pages = 352–355 | date = 17 March 2007 | doi = 10.1038/nature03379 | pmid = 15772653 | display-authors=8 | last1 = Murray | first1 = JB | last2 = Muller | first2 = JP | last3 = Neukum | first3 = G | last4 = Werner | first4 = SC | last5 = Van Gasselt | first5 = S | last6 = Hauber | first6 = E | last7 = Markiewicz | first7 = WJ | last8 = Head Jw | first8 = 3rd | last9 = Foing | first9 = BH | last10 = Page | first10 = David | last11 = Mitchell | first11 = Karl L. | last12 = Portyankina | first12 = Ganna | last13 = Co-Investigator Team | first13 = The Hrsc | issue = 7031 |bibcode = 2005Natur.434..352M | s2cid = 4373323 }}</ref>

==Overview== <gallery mode="packed" heights="300"> File:USGS-Mars-MC-15-ElysiumRegion-mola.png|[[Elysium quadrangle]] MOLA map, with Elysium Planitia at bottom File:USGS-Mars-MC-23-AeolisRegion-mola.png|[[Aeolis quadrangle]] MOLA map, with Elysium Planitia at top </gallery>

==Exploration== [[NASA|NASA's]] ''[[InSight]]'' mission landed in Elysium Planitia on 26 November 2018.<ref>{{cite web |title=Landing Status {{!}} Landing – NASA's InSight Mars Lander |url=https://mars.nasa.gov/insight/timeline/landing/status/ |website=NASA's InSight Mars Lander |date=16 April 2024 |language=en}}</ref> It took off from Earth on 5 May 2018. The probe will study the internal structure of Mars and by so doing improve understanding of the planet's evolution. InSight Mars lander was able to take color pictures from the surface Elysium Planitia and sent them by radio signal back to Earth. During the descent sequence two additional items were jettisoned, the backshell with parachute, and heat shield, and they impacted in the vicinity of the lander.

{{Multiple image | align = left | image1 = PIA22829 InSight's First Image from Mars.png | image3 = PIA22575 IDC Camera First Image.jpg | width = 300 | footer = First images of Elysium Planitia from ''InSight'''s Instrument Context Camera (ICC, left), without lens cover and stretched (ICC, Middle), and the Instrument Deployment Camera (IDC, right) }} {{clear}}

In March 2017, scientists from the [[Jet Propulsion Laboratory]] announced that the landing site had been selected. It is located in western Elysium Planitia at {{Coord|4.5|N|135.9|E|globe:mars_type:landmark|name=''InSight'' landing site}}.<ref>{{cite conference |title=Selection of the 2018 Insight Landing Site |conference=48th Lunar and Planetary Science Conference. 20–24 March 2017. The Woodlands, Texas. |first1=M. |last1=Golombek |first2=D. |last2=Kipp |first3=I. J. |last3=Daubar |first4=D. |last4=Kass |first5=M. |last5=Mischna |first6=W.B. |last6=Banerdt |display-authors=1 |date=2017 |bibcode=2017LPI....48.1515G |id=LPI Contribution No. 1964, id.1515}}</ref> The landing site is about {{convert|600|km|mi|abbr=on}} north from where the [[Curiosity (rover)|''Curiosity'' rover]] is operating in [[Gale (crater)|Gale Crater]].<ref>{{cite web |url=https://marsmobile.jpl.nasa.gov/multimedia/images/2018/insights-landing-site-elysium-planitia |archive-url= https://web.archive.org/web/20190102134049/https://marsmobile.jpl.nasa.gov/multimedia/images/2018/insights-landing-site-elysium-planitia|archive-date= 2 January 2019|title=''InSight''{{'}}s Landing Site: Elysium Planitia |publisher=NASA |date=25 January 2018 |access-date=1 February 2018 }}</ref>

{{multiple image | align = none | total_width = 800 | image2 = PIA21489 - Advance Inspection of NASA's Next Mars Landing Site.jpg | caption2 = Image footprints by HiRise on ''Mars Reconnaissance Orbiter'' for studying the planned ''Insight'' landing ellipse. From east to west the scale is about {{convert|100|mi|km|order=flip|abbr=on}}. | image4 = PIA22878-Mars-InSightLander-FinalLocation-20181213.jpg | caption4 = <div class="center">''InSight'' final landing location (red dot)<br />(13 December 2018)</div> }}

{{multiple image | align = none | total_width = 800 | image4 = PIA22875-InSightOnMarsSurface-ParachuteLanderHeatshield-20181211.jpg | caption4 = InSight backshell with parachute, lander, heat shield (11 December 2018) | image5 = PIA22875-InSightOnMarsSurface-ParachuteLanderHeatshield-20181126.jpg | caption5 = InSight backshell with parachute, lander, heat shield<br />(26 November 2018) }}

==Landforms==

<gallery class="center" widths="190" heights="180"> File:ESP 048878 2095fractures.jpg|Wide view of fractured ground, as seen by HiRISE under [[HiWish program]] File:48878 2095fractures.jpg|Close view of fractured ground, as seen by HiRISE under HiWish program File:47441 1800moundsstreaks.jpg|Layered mesa and mounds with dark slope streaks, as seen by HiRISE under HiWish program File:47441 1800mesaclose.jpg|Close view of layered small mesa with dark slope streak, as seen by HiRISE under HiWish program. Box shows the size of a football field. </gallery>

==Cones== <gallery class="center" widths="190px" heights="180px"> ESP 045885 2070cones.jpg|Cones, as seen by HiRISE under HiWish program. These cones probably formed when hot lava flowed over ice-rich ground. 45885 2070cones.jpg|Close view of cones, as seen by HiRISE under HiWish program. These cones probably formed when hot lava flowed over ice-rich ground. </gallery>

==Gallery== <gallery class="center" widths="190" heights="180"> </gallery> <gallery class="center" widths="190" heights="180"> File:Wikiesp036510 1735layersmound.jpg|Mound showing layers at the base, as seen by HiRISE under HiWish program. Location is east of Gale Crater in the [[Aeolis quadrangle]]. File:Wikiesp036510 1735layersyardang.jpg|Yardangs showing layers, as seen by HiRISE under HiWish program. Location is east of Gale Crater in the [[Aeolis quadrangle]]. File:40795 1815mesa.jpg|Mesas and eroded parts of mesas showing layers and [[dark slope streaks]], as seen by HiRISE under HiWish program. Image is located in eastern [[Avernus Colles]]. File:ESP 045029 1785moundlayers.jpg|Wide view of layered terrain, as seen by HiRISE under HiWish program. Location is northeast of Gale Crater. </gallery>

==See also== * [[Fossa (geology)]] * [[Geography of Mars]] * [[Geology of Mars]] * [[List of plains on Mars]] * [[List of quadrangles on Mars]]

==References== {{Reflist}}

==External links== * [http://www.google.com/mars/#lat=14.859850&lon=158.115234&zoom=4&q=Elysium%20Planitia Google Mars] – zoomable map centered on Elysium Planitia, with three main volcanoes of Elysium visible * [http://www.google.com/mars/#lat=9.876863&lon=157.719726&zoom=8&map=infrared&q=Cerberus%20Fossae Google Mars – Cerebrus Fossae fissures]

[[Category:Plains on Mars]] [[Category:InSight]] [[Category:Elysium quadrangle]] [[Category:Aeolis quadrangle]]