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Available in 23 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-23" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">23 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Catalan" lang="ca" hreflang="ca" data-title="Planum Boreum" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Czech" lang="cs" hreflang="cs" data-title="Planum Boreum" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – German" lang="de" hreflang="de" data-title="Planum Boreum" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/%CE%92%CF%8C%CF%81%CE%B5%CE%B9%CE%B1_%CE%A0%CE%BF%CE%BB%CE%B9%CE%BA%CE%AE_%CE%9B%CE%B5%CE%BA%CE%AC%CE%BD%CE%B7" title="Βόρεια Πολική Λεκάνη – Greek" lang="el" hreflang="el" data-title="Βόρεια Πολική Λεκάνη" data-language-autonym="Ελληνικά" data-language-local-name="Greek" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Spanish" lang="es" hreflang="es" data-title="Planum Boreum" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D9%81%D9%84%D8%A7%D8%AA%D9%87_%D8%B4%D9%85%D8%A7%D9%84%DB%8C" title="فلاته شمالی – Persian" lang="fa" hreflang="fa" data-title="فلاته شمالی" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – French" lang="fr" hreflang="fr" data-title="Planum Boreum" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Galician" lang="gl" hreflang="gl" data-title="Planum Boreum" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%AA%E0%A5%8D%E0%A4%B2%E0%A5%88%E0%A4%A8%E0%A4%AE_%E0%A4%AC%E0%A5%8B%E0%A4%B0%E0%A5%87%E0%A4%AF%E0%A4%AE" title="प्लैनम बोरेयम – Hindi" lang="hi" hreflang="hi" data-title="प्लैनम बोरेयम" data-language-autonym="हिन्दी" data-language-local-name="Hindi" class="interlanguage-link-target"><span>हिन्दी</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Indonesian" lang="id" hreflang="id" data-title="Planum Boreum" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Italian" lang="it" hreflang="it" data-title="Planum Boreum" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-la mw-list-item"><a href="https://la.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Latin" lang="la" hreflang="la" data-title="Planum Boreum" data-language-autonym="Latina" data-language-local-name="Latin" class="interlanguage-link-target"><span>Latina</span></a></li><li class="interlanguage-link interwiki-lb mw-list-item"><a href="https://lb.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Luxembourgish" lang="lb" hreflang="lb" data-title="Planum Boreum" data-language-autonym="Lëtzebuergesch" data-language-local-name="Luxembourgish" class="interlanguage-link-target"><span>Lëtzebuergesch</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Hungarian" lang="hu" hreflang="hu" data-title="Planum Boreum" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Planum Boreum" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Nordpolomr%C3%A5det_til_Mars" title="Nordpolområdet til Mars – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Nordpolområdet til Mars" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Polish" lang="pl" hreflang="pl" data-title="Planum Boreum" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Portuguese" lang="pt" hreflang="pt" data-title="Planum Boreum" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Russian" lang="ru" hreflang="ru" data-title="Planum Boreum" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Slovak" lang="sk" hreflang="sk" data-title="Planum Boreum" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%9F%D0%BB%D0%B0%D1%82%D0%BE_%D0%9F%D1%96%D0%B2%D0%BD%D1%96%D1%87%D0%BD%D0%B5" title="Плато Північне – Ukrainian" lang="uk" hreflang="uk" data-title="Плато Північне" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/Planum_Boreum" title="Planum Boreum – Vietnamese" lang="vi" hreflang="vi" data-title="Planum Boreum" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E5%8C%97%E6%A5%B5%E9%AB%98%E5%8E%9F" title="北極高原 – Chinese" lang="zh" hreflang="zh" data-title="北極高原" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q578739#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div 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.latitude{white-space:nowrap}</style><span class="plainlinks nourlexpansion"><a class="external text" href="https://geohack.toolforge.org/geohack.php?pagename=Planum_Boreum&params=88.0_N_15.0_E_globe:mars_type:landmark"><span class="geo-nondefault"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">88°00′N</span> <span class="longitude">15°00′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-default"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">88.0°N 15.0°E</span><span style="display:none"> / <span class="geo">88.0; 15.0</span></span></span></a></span></span></div></div> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Planum on Mars</div> <style data-mw-deduplicate="TemplateStyles:r1257001546">.mw-parser-output .infobox-subbox{padding:0;border:none;margin:-3px;width:auto;min-width:100%;font-size:100%;clear:none;float:none;background-color:transparent}.mw-parser-output .infobox-3cols-child{margin:auto}.mw-parser-output .infobox .navbar{font-size:100%}@media screen{html.skin-theme-clientpref-night .mw-parser-output .infobox-full-data:not(.notheme)>div:not(.notheme)[style]{background:#1f1f23!important;color:#f8f9fa}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .infobox-full-data:not(.notheme) div:not(.notheme){background:#1f1f23!important;color:#f8f9fa}}@media(min-width:640px){body.skin--responsive .mw-parser-output .infobox-table{display:table!important}body.skin--responsive .mw-parser-output .infobox-table>caption{display:table-caption!important}body.skin--responsive .mw-parser-output .infobox-table>tbody{display:table-row-group}body.skin--responsive .mw-parser-output .infobox-table tr{display:table-row!important}body.skin--responsive .mw-parser-output .infobox-table th,body.skin--responsive .mw-parser-output .infobox-table td{padding-left:inherit;padding-right:inherit}}</style><table class="infobox"><caption class="infobox-title">Planum Boreum</caption><tbody><tr><td colspan="2" class="infobox-image"><span typeof="mw:File"><a href="/wiki/File:Mars_NPArea-PIA00161.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/2/2c/Mars_NPArea-PIA00161.jpg/200px-Mars_NPArea-PIA00161.jpg" decoding="async" width="200" height="200" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/2/2c/Mars_NPArea-PIA00161.jpg/300px-Mars_NPArea-PIA00161.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/2/2c/Mars_NPArea-PIA00161.jpg/400px-Mars_NPArea-PIA00161.jpg 2x" data-file-width="6744" data-file-height="6744" /></a></span><div class="infobox-caption"><a href="/wiki/Viking_(spacecraft)" class="mw-redirect" title="Viking (spacecraft)">Viking</a> mosaic of Planum Boreum and surrounds</div></td></tr><tr><th scope="row" class="infobox-label">Coordinates</th><td class="infobox-data"><span class="geo-inline"><style data-mw-deduplicate="TemplateStyles:r1156832818">.mw-parser-output .geo-default,.mw-parser-output .geo-dms,.mw-parser-output .geo-dec{display:inline}.mw-parser-output .geo-nondefault,.mw-parser-output .geo-multi-punct,.mw-parser-output .geo-inline-hidden{display:none}.mw-parser-output .longitude,.mw-parser-output .latitude{white-space:nowrap}</style><span class="plainlinks nourlexpansion"><a class="external text" href="https://geohack.toolforge.org/geohack.php?pagename=Planum_Boreum&params=88.0_N_15.0_E_globe:mars_type:landmark"><span class="geo-nondefault"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">88°00′N</span> <span class="longitude">15°00′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-default"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">88.0°N 15.0°E</span><span style="display:none"> / <span class="geo">88.0; 15.0</span></span></span></a></span></span></td></tr></tbody></table> <p><b>Planum Boreum</b> (<a href="/wiki/Latin" title="Latin">Latin</a>: "the northern plain") is the northern polar plain on <a href="/wiki/Mars" title="Mars">Mars</a>. It extends northward from roughly 80°N and is centered at <span class="geo-inline"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1156832818"><span class="plainlinks nourlexpansion"><a class="external text" href="https://geohack.toolforge.org/geohack.php?pagename=Planum_Boreum&params=88_N_15_E_globe:Mars"><span class="geo-nondefault"><span class="geo-dms" title="Maps, aerial photos, and other data for this location"><span class="latitude">88°00′N</span> <span class="longitude">15°00′E</span></span></span><span class="geo-multi-punct"> / </span><span class="geo-default"><span class="geo-dec" title="Maps, aerial photos, and other data for this location">88.0°N 15.0°E</span><span style="display:none"> / <span class="geo">88.0; 15.0</span></span></span></a></span></span>. Surrounding the high polar plain is a flat and featureless lowland plain called <a href="/wiki/Vastitas_Borealis" title="Vastitas Borealis">Vastitas Borealis</a> which extends for approximately 1500 kilometers southwards, dominating the northern hemisphere.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Features">Features</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Planum_Boreum&action=edit&section=1" title="Edit section: Features"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure typeof="mw:File/Thumb"><a href="/wiki/File:MRO_image_of_Mars_North_Pole.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/c3/MRO_image_of_Mars_North_Pole.jpg/150px-MRO_image_of_Mars_North_Pole.jpg" decoding="async" width="150" height="380" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/c3/MRO_image_of_Mars_North_Pole.jpg/225px-MRO_image_of_Mars_North_Pole.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/c3/MRO_image_of_Mars_North_Pole.jpg/300px-MRO_image_of_Mars_North_Pole.jpg 2x" data-file-width="2000" data-file-height="5060" /></a><figcaption>False color <a href="/wiki/HiRISE" title="HiRISE">HiRISE</a> image of a side of the <a href="/wiki/Chasma_Boreale" title="Chasma Boreale">Chasma Boreale</a>, a canyon in the polar ice cap. Light browns are layers of surface dust greys and blues are layers of water and carbon dioxide ice. Regular geometric cracking is indicative of higher concentrations of water ice.</figcaption></figure> <p>The main feature of the Planum Boreum is a large fissure or canyon in the polar ice cap called <a href="/wiki/Chasma_Boreale" title="Chasma Boreale">Chasma Boreale</a>. It is up to 100 kilometres (62 mi) wide and features scarps up to 2 kilometres (1.2 mi) high.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-usgs_3-0" class="reference"><a href="#cite_note-usgs-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> By comparison, the <a href="/wiki/Grand_Canyon" title="Grand Canyon">Grand Canyon</a> is approximately 1.6 kilometres (1 mi) deep in some places and 446 kilometres (277 mi) long but only up to 24 kilometres (15 mi) wide. Chasma Boreale cuts through polar deposits and ice, such as those present at <a href="/wiki/Greenland" title="Greenland">Greenland</a>. </p><p>Planum Boreum interfaces with Vastitas Borealis west of Chasma Boreale at an irregular scarp named <a href="/wiki/Rupes_Tenuis" title="Rupes Tenuis">Rupes Tenuis</a>. This scarp reaches heights of up to 1 km. At other places, the interface is a collection of mesas and troughs. </p><p>Planum Boreum is surrounded by large fields of <a href="/wiki/Sand_dune" class="mw-redirect" title="Sand dune">sand dunes</a> spanning from 75°N to 85°N. These dune fields are named <a href="/wiki/Olympia_Undae" title="Olympia Undae">Olympia Undae</a>, <a href="/wiki/Abalos_Undae" title="Abalos Undae">Abalos Undae</a>, <a href="/wiki/Siton_Undae" title="Siton Undae">Siton Undae</a>, and <a href="/wiki/Hyperboreae_Undae" title="Hyperboreae Undae">Hyperboreae Undae</a>. Olympia Undae, by far the largest, covers from 100°E to 240°E. Abalos Undae covers from 261°E to 280°E and Hyperboreale Undae spans from 311°E to 341°E.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> See also <a href="/wiki/List_of_extraterrestrial_dune_fields" title="List of extraterrestrial dune fields">List of extraterrestrial dune fields</a>. </p> <div class="mw-heading mw-heading3"><h3 id="Ice_cap">Ice cap</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Planum_Boreum&action=edit&section=2" title="Edit section: Ice cap"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:PIA21465_-_North_Polar_Layers.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/0/00/PIA21465_-_North_Polar_Layers.jpg/220px-PIA21465_-_North_Polar_Layers.jpg" decoding="async" width="220" height="138" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/0/00/PIA21465_-_North_Polar_Layers.jpg/330px-PIA21465_-_North_Polar_Layers.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/0/00/PIA21465_-_North_Polar_Layers.jpg/440px-PIA21465_-_North_Polar_Layers.jpg 2x" data-file-width="2880" data-file-height="1800" /></a><figcaption>False color <a href="/wiki/HiRISE" title="HiRISE">HiRISE</a> view of water ice layers in Olympia Rupes, believed by scientists to be preserving climate conditions of Mars dating back millions of years. Depicted width: <style data-mw-deduplicate="TemplateStyles:r1154941027">.mw-parser-output .frac{white-space:nowrap}.mw-parser-output .frac .num,.mw-parser-output .frac .den{font-size:80%;line-height:0;vertical-align:super}.mw-parser-output .frac .den{vertical-align:sub}.mw-parser-output .sr-only{border:0;clip:rect(0,0,0,0);clip-path:polygon(0px 0px,0px 0px,0px 0px);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute;width:1px}</style>1.3 km (<span class="frac"><span class="num">3</span>⁄<span class="den">4</span></span> mi)</figcaption></figure> <p>Planum Boreum is home to a permanent <a href="/wiki/Polar_ice_cap" title="Polar ice cap">ice cap</a> consisting mainly of <a href="/wiki/Ice" title="Ice">water ice</a> (with a 1 m thick veneer of <a href="/wiki/Dry_ice" title="Dry ice">carbon dioxide ice</a> during the winter).<sup id="cite_ref-darling_marspoles_5-0" class="reference"><a href="#cite_note-darling_marspoles-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> It has a volume of 1.2 million cubic kilometres and covers an area equivalent to about 1.5 times the size of <a href="/wiki/Texas" title="Texas">Texas</a>. It has a radius of 600 km. The maximum depth of the cap is 3 km.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> </p><p>The spiral troughs in the ice cap are formed by <a href="/wiki/Katabatic_wind" title="Katabatic wind">katabatic winds</a> that entrain surface ice eroded from the equator-facing sides of the troughs, likely aided by solar ablation (<a href="/wiki/Sublimation_(phase_transition)" title="Sublimation (phase transition)">sublimation</a>), which is then redeposited on the colder pole-facing slopes. The troughs are roughly perpendicular to the wind direction, which is shifted by the <a href="/wiki/Coriolis_effect" class="mw-redirect" title="Coriolis effect">Coriolis effect</a>, leading to the spiral pattern.<sup id="cite_ref-Isaac_2010_7-0" class="reference"><a href="#cite_note-Isaac_2010-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> The troughs gradually migrate towards the pole over time; the central troughs have moved about 65 km in the last 2 million years.<sup id="cite_ref-Isaac_2010_7-1" class="reference"><a href="#cite_note-Isaac_2010-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Chasma_Boreale" title="Chasma Boreale">Chasma Boreale</a> is a canyon-like feature older than the troughs, and in contrast is aligned parallel to the wind direction.<sup id="cite_ref-Isaac_2010_7-2" class="reference"><a href="#cite_note-Isaac_2010-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p><p>The surface composition of the northern ice cap in middle spring (after a winter's accumulation of seasonal dry ice) has been studied from orbit. The outer edges of the ice cap are contaminated with dust (0.15% by weight) and are mostly water ice. As one moves toward the pole, the surface water ice content decreases and is replaced by dry ice. The purity of the ice also increases. At the pole, the surface seasonal ice consists of essentially pure dry ice with little dust content and 30 <a href="/wiki/Parts_per_million" class="mw-redirect" title="Parts per million">parts per million</a> of water ice.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> </p><p>The <a href="/wiki/Phoenix_(spacecraft)" title="Phoenix (spacecraft)">Phoenix</a> lander, launched in 2007, arrived at Mars in May 2008 and successfully landed in the Vastitas Borealis region of the planet on May 25, 2008. The north polar cap of Mars has been proposed as a landing site for a human Mars expedition by <a href="/wiki/Geoffrey_A._Landis" title="Geoffrey A. Landis">Geoffrey A. Landis</a><sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> and by <a href="/wiki/Charles_Cockell" class="mw-redirect" title="Charles Cockell">Charles Cockell</a>.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Recurring_phenomena">Recurring phenomena</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Planum_Boreum&action=edit&section=3" title="Edit section: Recurring phenomena"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading3"><h3 id="Avalanches">Avalanches</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Planum_Boreum&action=edit&section=4" title="Edit section: Avalanches"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A February 2008 HiRISE observation captured four <a href="/wiki/Avalanche" title="Avalanche">avalanches</a> in progress off a 700 metres (2,300 ft) cliff. The cloud of fine material is 180 metres (590 ft) across and extends 190 metres (620 ft) from the base of the cliff. The reddish layers are known to be rock rich in water ice while the white layers are seasonal carbon dioxide frost. The landslide is thought to have originated from the uppermost red layer. Follow-up observations are planned to characterize the nature of the landslide debris.<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> </p> <style data-mw-deduplicate="TemplateStyles:r1237032888/mw-parser-output/.tmulti">.mw-parser-output .tmulti .multiimageinner{display:flex;flex-direction:column}.mw-parser-output .tmulti .trow{display:flex;flex-direction:row;clear:left;flex-wrap:wrap;width:100%;box-sizing:border-box}.mw-parser-output .tmulti .tsingle{margin:1px;float:left}.mw-parser-output .tmulti .theader{clear:both;font-weight:bold;text-align:center;align-self:center;background-color:transparent;width:100%}.mw-parser-output .tmulti .thumbcaption{background-color:transparent}.mw-parser-output .tmulti .text-align-left{text-align:left}.mw-parser-output .tmulti .text-align-right{text-align:right}.mw-parser-output .tmulti .text-align-center{text-align:center}@media all and (max-width:720px){.mw-parser-output .tmulti .thumbinner{width:100%!important;box-sizing:border-box;max-width:none!important;align-items:center}.mw-parser-output .tmulti .trow{justify-content:center}.mw-parser-output .tmulti .tsingle{float:none!important;max-width:100%!important;box-sizing:border-box;text-align:center}.mw-parser-output .tmulti .tsingle .thumbcaption{text-align:left}.mw-parser-output .tmulti .trow>.thumbcaption{text-align:center}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .tmulti .multiimageinner img{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .tmulti .multiimageinner img{background-color:white}}</style><div class="thumb tmulti tleft"><div class="thumbinner multiimageinner" style="width:558px;max-width:558px"><div class="trow"><div class="theader">Avalanches on Mars</div></div><div class="trow"><div class="tsingle" style="width:302px;max-width:302px"><div class="thumbimage"><span typeof="mw:File"><a href="/wiki/File:Avalanche_on_North_pole_scarp_on_Mars.jpg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/b/b4/Avalanche_on_North_pole_scarp_on_Mars.jpg/300px-Avalanche_on_North_pole_scarp_on_Mars.jpg" decoding="async" width="300" height="188" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/b/b4/Avalanche_on_North_pole_scarp_on_Mars.jpg/450px-Avalanche_on_North_pole_scarp_on_Mars.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/b/b4/Avalanche_on_North_pole_scarp_on_Mars.jpg/600px-Avalanche_on_North_pole_scarp_on_Mars.jpg 2x" data-file-width="2880" data-file-height="1800" /></a></span></div><div class="thumbcaption text-align-center">November 27, 2011</div></div><div class="tsingle" style="width:252px;max-width:252px"><div class="thumbimage"><span typeof="mw:File"><a href="/wiki/File:PIA24035-Mars-Avalanche-20190529.jpg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/e/ef/PIA24035-Mars-Avalanche-20190529.jpg/250px-PIA24035-Mars-Avalanche-20190529.jpg" decoding="async" width="250" height="188" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/ef/PIA24035-Mars-Avalanche-20190529.jpg/375px-PIA24035-Mars-Avalanche-20190529.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/ef/PIA24035-Mars-Avalanche-20190529.jpg/500px-PIA24035-Mars-Avalanche-20190529.jpg 2x" data-file-width="1024" data-file-height="768" /></a></span></div><div class="thumbcaption text-align-center">May 29, 2019</div></div></div></div></div> <div style="clear:both;" class=""></div> <div class="mw-heading mw-heading3"><h3 id="Repeating_annular_cloud">Repeating annular cloud</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Planum_Boreum&action=edit&section=5" title="Edit section: Repeating annular cloud"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Mars_cyclone.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/d/de/Mars_cyclone.jpg/220px-Mars_cyclone.jpg" decoding="async" width="220" height="134" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/de/Mars_cyclone.jpg/330px-Mars_cyclone.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/d/de/Mars_cyclone.jpg 2x" data-file-width="420" data-file-height="256" /></a><figcaption>Hubble view of the colossal polar cloud on Mars</figcaption></figure> <p>A large doughnut-shaped cloud appears in North polar region of Mars around the same time every Martian year and of about the same size.<sup id="cite_ref-mgs_14-0" class="reference"><a href="#cite_note-mgs-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> It forms in the morning, dissipates by the Martian afternoon.<sup id="cite_ref-mgs_14-1" class="reference"><a href="#cite_note-mgs-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> The outer diameter of the cloud is roughly 1,600 km (1,000 mi), and the inner hole or eye is 320 km (200 mi) across.<sup id="cite_ref-cornell_15-0" class="reference"><a href="#cite_note-cornell-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> The cloud is thought to be composed of water-ice,<sup id="cite_ref-cornell_15-1" class="reference"><a href="#cite_note-cornell-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> so it is white in color, unlike the more common dust storms. </p><p>It looks like a cyclonic storm, similar to hurricane, but it does not rotate.<sup id="cite_ref-mgs_14-2" class="reference"><a href="#cite_note-mgs-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> The cloud appears during the northern summer and at high latitude. Speculation is that this is due to unique climate conditions near the northern pole.<sup id="cite_ref-cornell_15-2" class="reference"><a href="#cite_note-cornell-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> Cyclone-like storms were first detected during the Viking orbital mapping program, but the northern annular cloud is nearly three times larger.<sup id="cite_ref-cornell_15-3" class="reference"><a href="#cite_note-cornell-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> The cloud has also been detected by various probes and telescopes including the <a href="/wiki/Hubble_Space_Telescope" title="Hubble Space Telescope">Hubble</a> and <a href="/wiki/Mars_Global_Surveyor" title="Mars Global Surveyor">Mars Global Surveyor</a>.<sup id="cite_ref-mgs_14-3" class="reference"><a href="#cite_note-mgs-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-cornell_15-4" class="reference"><a href="#cite_note-cornell-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> </p><p>When <a href="/wiki/Hubble_Space_Telescope" title="Hubble Space Telescope">Hubble Space Telescope</a> viewed it in 1999, it was thought to be <a href="/wiki/Cyclonic_storm" class="mw-redirect" title="Cyclonic storm">cyclonic storm</a>. The diameter was measured to be approximately 1750 km, and featured an "eye" 320 km in diameter.<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Planum_Boreum&action=edit&section=6" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Abalos_Mensa" title="Abalos Mensa">Abalos Mensa</a></li> <li><a href="/wiki/Aspledon_Undae" title="Aspledon Undae">Aspledon Undae</a></li> <li><a href="/wiki/Martian_polar_ice_caps" title="Martian polar ice caps">Martian polar ice caps</a></li> <li><a href="/wiki/Planum_Australe" title="Planum Australe">Planum Australe</a>, the south polar plain</li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Planum_Boreum&action=edit&section=7" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external autonumber" href="https://planetarynames.wr.usgs.gov/jsp/FeatureNameDetail.jsp?feature=64923">[1]</a> and <a rel="nofollow" class="external autonumber" href="https://planetarynames.wr.usgs.gov/jsp/FeatureNameDetail.jsp?feature=66502">[2]</a> give Vastitas Borealis starting at 54.7°N and Planum Boreum at 78.5°N. The radius of Mars is approximately 3400 km, so <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle d={\frac {78.5-54.7}{360}}\times 2\pi \ \times 3400{\mbox{ km}}=1412{\mbox{ km}}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>d</mi> <mo>=</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mrow> <mn>78.5</mn> <mo>−</mo> <mn>54.7</mn> </mrow> <mn>360</mn> </mfrac> </mrow> <mo>×</mo> <mn>2</mn> <mi>π</mi> <mtext> </mtext> <mo>×</mo> <mn>3400</mn> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="false" scriptlevel="0"> <mtext> km</mtext> </mstyle> </mrow> <mo>=</mo> <mn>1412</mn> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="false" scriptlevel="0"> <mtext> km</mtext> </mstyle> </mrow> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle d={\frac {78.5-54.7}{360}}\times 2\pi \ \times 3400{\mbox{ km}}=1412{\mbox{ km}}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/d3096d72cf300e9eb06d2e3699d2679debf756ee" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -1.838ex; width:44.901ex; height:5.176ex;" alt="{\displaystyle d={\frac {78.5-54.7}{360}}\times 2\pi \ \times 3400{\mbox{ km}}=1412{\mbox{ km}}}"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.esa.int/SPECIALS/Mars_Express/SEM8T86Y3EE_0.html">"Fly over the Chasma Boreale at Martian north pole"</a>. <a href="/wiki/European_Space_Agency" title="European Space Agency">European Space Agency</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2006-11-01</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Fly+over+the+Chasma+Boreale+at+Martian+north+pole&rft.pub=European+Space+Agency&rft_id=http%3A%2F%2Fwww.esa.int%2FSPECIALS%2FMars_Express%2FSEM8T86Y3EE_0.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3APlanum+Boreum" class="Z3988"></span></span> </li> <li id="cite_note-usgs-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-usgs_3-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://pubs.usgs.gov/sim/2005/2888/sim2888pamphlet.pdf">"Geologic Map of the Northern Plains of Mars"</a> <span class="cs1-format">(PDF)</span>. <a href="/wiki/United_States_Geological_Survey" title="United States Geological Survey">United States Geological Survey</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2006-01-11</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Geologic+Map+of+the+Northern+Plains+of+Mars&rft.pub=United+States+Geological+Survey&rft_id=http%3A%2F%2Fpubs.usgs.gov%2Fsim%2F2005%2F2888%2Fsim2888pamphlet.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3APlanum+Boreum" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://planetarynames.wr.usgs.gov/jsp/AdvanceSearch2.jsp?system=ALL&system=ALL&fname=undae&ft=ALL&diamgt=&diamlt=&nlat=&slat=&wlon=&elon=&lonDirection=null&adb=&ade=&as=ANY&cont=&ethn=&refN=&refT=&quad=&map=&QuickSearch=true&sort=AP">"USGS Astro: Search Planetary Nomenclature"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2006-11-01</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=USGS+Astro%3A+Search+Planetary+Nomenclature&rft_id=http%3A%2F%2Fplanetarynames.wr.usgs.gov%2Fjsp%2FAdvanceSearch2.jsp%3Fsystem%3DALL%26system%3DALL%26fname%3Dundae%26ft%3DALL%26diamgt%3D%26diamlt%3D%26nlat%3D%26slat%3D%26wlon%3D%26elon%3D%26lonDirection%3Dnull%26adb%3D%26ade%3D%26as%3DANY%26cont%3D%26ethn%3D%26refN%3D%26refT%3D%26quad%3D%26map%3D%26QuickSearch%3Dtrue%26sort%3DAP&rfr_id=info%3Asid%2Fen.wikipedia.org%3APlanum+Boreum" class="Z3988"></span></span> </li> <li id="cite_note-darling_marspoles-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-darling_marspoles_5-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDarling" class="citation encyclopaedia cs1">Darling, David. <a rel="nofollow" class="external text" href="http://www.daviddarling.info/encyclopedia/M/Marspoles.html">"Mars, polar caps"</a>. <i>Encyclopedia of Astrobiology, Astronomy, and Spaceflight</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2007-02-26</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=Mars%2C+polar+caps&rft.btitle=Encyclopedia+of+Astrobiology%2C+Astronomy%2C+and+Spaceflight&rft.aulast=Darling&rft.aufirst=David&rft_id=http%3A%2F%2Fwww.daviddarling.info%2Fencyclopedia%2FM%2FMarspoles.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3APlanum+Boreum" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20061017122112/http://ltpwww.gsfc.nasa.gov/tharsis/agu_f98.html">"Laser provides first 3-D View of Mars' North Pole"</a>. Archived from <a rel="nofollow" class="external text" href="https://ltpwww.gsfc.nasa.gov/tharsis/agu_f98.html">the original</a> on 2006-10-17<span class="reference-accessdate">. Retrieved <span class="nowrap">2006-11-01</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Laser+provides+first+3-D+View+of+Mars%27+North+Pole&rft_id=http%3A%2F%2Fltpwww.gsfc.nasa.gov%2Ftharsis%2Fagu_f98.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3APlanum+Boreum" class="Z3988"></span></span> </li> <li id="cite_note-Isaac_2010-7"><span class="mw-cite-backlink">^ <a href="#cite_ref-Isaac_2010_7-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Isaac_2010_7-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-Isaac_2010_7-2"><sup><i><b>c</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSmith,_Isaac_B.Holt,_J._W.2010" class="citation journal cs1">Smith, Isaac B.; Holt, J. W. (2010). "Onset and migration of spiral troughs on Mars revealed by orbital radar". <i>Nature</i>. <b>465</b> (4): <span class="nowrap">450–</span>453. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2010Natur.465..450S">2010Natur.465..450S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2Fnature09049">10.1038/nature09049</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/20505722">20505722</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature&rft.atitle=Onset+and+migration+of+spiral+troughs+on+Mars+revealed+by+orbital+radar&rft.volume=465&rft.issue=4&rft.pages=%3Cspan+class%3D%22nowrap%22%3E450-%3C%2Fspan%3E453&rft.date=2010&rft_id=info%3Apmid%2F20505722&rft_id=info%3Adoi%2F10.1038%2Fnature09049&rft_id=info%3Abibcode%2F2010Natur.465..450S&rft.au=Smith%2C+Isaac+B.&rft.au=Holt%2C+J.+W.&rfr_id=info%3Asid%2Fen.wikipedia.org%3APlanum+Boreum" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.space.com/8494-mystery-spirals-mars-finally-explained.html">"Mystery Spirals on Mars Finally Explained"</a>. Space.com. 26 May 2010<span class="reference-accessdate">. Retrieved <span class="nowrap">2010-05-26</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Mystery+Spirals+on+Mars+Finally+Explained&rft.pub=Space.com&rft.date=2010-05-26&rft_id=http%3A%2F%2Fwww.space.com%2F8494-mystery-spirals-mars-finally-explained.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3APlanum+Boreum" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www-mars.lmd.jussieu.fr/granada2006/abstracts/Giuranna_Granada2006.pdf">"Spatial variability and composition of the seasonal north polar cap on Mars"</a> <span class="cs1-format">(PDF)</span><span class="reference-accessdate">. Retrieved <span class="nowrap">2006-11-01</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Spatial+variability+and+composition+of+the+seasonal+north+polar+cap+on+Mars&rft_id=http%3A%2F%2Fwww-mars.lmd.jussieu.fr%2Fgranada2006%2Fabstracts%2FGiuranna_Granada2006.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3APlanum+Boreum" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text">G. Landis, <a rel="nofollow" class="external text" href="http://www.sff.net/people/Geoffrey.Landis/pole.html">Polar Landing Site for a First Mars Expedition</a> Founding Convention of the Mars Society, August 13–16, 1998, <a href="/wiki/University_of_Colorado_at_Boulder" class="mw-redirect" title="University of Colorado at Boulder">University of Colorado</a> in <a href="/wiki/Boulder,_CO" class="mw-redirect" title="Boulder, CO">Boulder, CO</a></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><a href="/wiki/Project_Boreas" title="Project Boreas">Project Boreas</a> C. Cockell (editor), <a rel="nofollow" class="external text" href="http://www.bis-spaceflight.com/sitesia.aspx/page/170/id/980/l/en-gbBoreas">Project Boreas – A Station for the Martian Geographic North Pole</a><sup class="noprint Inline-Template"><span style="white-space: nowrap;">[<i><a href="/wiki/Wikipedia:Link_rot" title="Wikipedia:Link rot"><span title=" Dead link tagged December 2017">permanent dead link</span></a></i><span style="visibility:hidden; color:transparent; padding-left:2px">‍</span>]</span></sup>, The <a href="/wiki/British_Interplanetary_Society" title="British Interplanetary Society">British Interplanetary Society</a> (2006)</span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.sciam.com/gallery_directory.cfm?photo_id=7B82B079-C057-F0CF-D15B555DBA34B1CF">"Avalanche on Mars"</a>. <a href="/wiki/Scientific_American" title="Scientific American">Scientific American</a>. 2008-03-04<span class="reference-accessdate">. Retrieved <span class="nowrap">2008-03-05</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Avalanche+on+Mars&rft.pub=Scientific+American&rft.date=2008-03-04&rft_id=http%3A%2F%2Fwww.sciam.com%2Fgallery_directory.cfm%3Fphoto_id%3D7B82B079-C057-F0CF-D15B555DBA34B1CF&rfr_id=info%3Asid%2Fen.wikipedia.org%3APlanum+Boreum" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.jpl.nasa.gov/news/news.cfm?release=2008-036">"NASA Spacecraft Photographs Avalanches on Mars"</a>. 2008-03-03<span class="reference-accessdate">. Retrieved <span class="nowrap">2008-03-05</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=NASA+Spacecraft+Photographs+Avalanches+on+Mars&rft.date=2008-03-03&rft_id=http%3A%2F%2Fwww.jpl.nasa.gov%2Fnews%2Fnews.cfm%3Frelease%3D2008-036&rfr_id=info%3Asid%2Fen.wikipedia.org%3APlanum+Boreum" class="Z3988"></span></span> </li> <li id="cite_note-mgs-14"><span class="mw-cite-backlink">^ <a href="#cite_ref-mgs_14-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-mgs_14-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-mgs_14-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-mgs_14-3"><sup><i><b>d</b></i></sup></a></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://mars.jpl.nasa.gov/mgs/gallery/20050912-repeatNPWIC.html">Mars Global Surveyor – "8 Year Anniversary"</a></span> </li> <li id="cite_note-cornell-15"><span class="mw-cite-backlink">^ <a href="#cite_ref-cornell_15-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-cornell_15-1"><sup><i><b>b</b></i></sup></a> <a href="#cite_ref-cornell_15-2"><sup><i><b>c</b></i></sup></a> <a href="#cite_ref-cornell_15-3"><sup><i><b>d</b></i></sup></a> <a href="#cite_ref-cornell_15-4"><sup><i><b>e</b></i></sup></a></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDavid_BrandRay_Villard1999" class="citation web cs1">David Brand & Ray Villard (19 May 1999). <a rel="nofollow" class="external text" href="http://www.news.cornell.edu/releases/May99/mars.cyclone.deb.html">"Colossal cyclone swirling near Martian north pole is observed by Cornell-led team on Hubble telescope"</a>. Cornell News<span class="reference-accessdate">. Retrieved <span class="nowrap">2007-09-06</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Colossal+cyclone+swirling+near+Martian+north+pole+is+observed+by+Cornell-led+team+on+Hubble+telescope&rft.pub=Cornell+News&rft.date=1999-05-19&rft.au=David+Brand&rft.au=Ray+Villard&rft_id=http%3A%2F%2Fwww.news.cornell.edu%2Freleases%2FMay99%2Fmars.cyclone.deb.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3APlanum+Boreum" class="Z3988"></span></span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://hubblesite.org/newscenter/archive/releases/1999/22/text/">"Colossal Cyclone Swirls near Martian North Pole"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">2006-11-01</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Colossal+Cyclone+Swirls+near+Martian+North+Pole&rft_id=http%3A%2F%2Fhubblesite.org%2Fnewscenter%2Farchive%2Freleases%2F1999%2F22%2Ftext%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3APlanum+Boreum" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Planum_Boreum&action=edit&section=8" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="http://www.esa.int/SPECIALS/Mars_Express/SEM8T86Y3EE_0.html">Fly over the Chasma Boreale at Martian north pole</a> – courtesy of <a href="/wiki/Mars_Express" title="Mars Express">Mars Express</a></li> <li><a rel="nofollow" class="external text" href="https://pubs.usgs.gov/sim/2005/2888/">Geologic Map of the Northern Plains of Mars</a></li> <li><a rel="nofollow" class="external text" href="http://hirise.lpl.arizona.edu/PSP_007338_2640">HiRISE image of Martian landslides</a></li> <li><a rel="nofollow" class="external text" href="http://hiroc.lpl.arizona.edu/images/PSP/PSP_001370_2505/">HiRISE image of permanent ice mound separated from cap</a></li> <li>Various <a href="/wiki/HiRISE" title="HiRISE">HiRISE</a> images of the north polar ice cap: <a rel="nofollow" class="external autonumber" href="http://hiroc.lpl.arizona.edu/images/PSP/PSP_001412_2650/">[3]</a> <a rel="nofollow" class="external autonumber" href="http://hiroc.lpl.arizona.edu/images/PSP/PSP_001334_2645/color.html">[4]</a> <a rel="nofollow" class="external autonumber" href="http://hiroc.lpl.arizona.edu/images/PSP/PSP_001513_2650/">[5]</a> <a rel="nofollow" class="external autonumber" href="http://hiroc.lpl.arizona.edu/images/PSP/PSP_001406_2680/">[6]</a></li></ul> <div class="navbox-styles"><style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · 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class="navbox-group" style="width:1%"><a href="/wiki/Areography" title="Areography">Geography</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Atmosphere_of_Mars" title="Atmosphere of Mars">Atmosphere</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Mars_general_circulation_model" title="Mars general circulation model">Circulation</a></li> <li><a href="/wiki/Climate_of_Mars" title="Climate of Mars">Climate</a></li> <li><a href="/wiki/Martian_dust_devils" title="Martian dust devils">Dust devil tracks</a></li> <li><a href="/wiki/Natural_methane_on_Mars" title="Natural methane on Mars">Methane</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/List_of_terrae_on_Mars" title="List of terrae on Mars">Regions</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Arabia_Terra" title="Arabia Terra">Arabia Terra</a></li> <li><a href="/wiki/Cerberus_(Mars)" title="Cerberus (Mars)">Cerberus (Mars)</a></li> <li><a href="/wiki/Cydonia_(Mars)" title="Cydonia (Mars)">Cydonia</a></li> <li><a href="/wiki/Eridania_Lake" title="Eridania Lake">Eridania Lake</a></li> <li><a href="/wiki/Iani_Chaos" title="Iani Chaos">Iani Chaos</a></li> <li><a href="/wiki/Olympia_Undae" title="Olympia Undae">Olympia Undae</a></li> <li><a href="/wiki/Planum_Australe" title="Planum Australe">Planum Australe</a></li> <li><a class="mw-selflink selflink">Planum Boreum</a></li> <li><a href="/wiki/List_of_quadrangles_on_Mars" title="List of quadrangles on Mars">Quadrangles</a></li> <li><a href="/wiki/Sinus_Meridiani" title="Sinus Meridiani">Sinus Meridiani</a></li> <li><a href="/wiki/Tempe_Terra" title="Tempe Terra">Tempe Terra</a></li> <li><a href="/wiki/Terra_Cimmeria" title="Terra Cimmeria">Terra Cimmeria</a></li> <li><a href="/wiki/Terra_Sabaea" title="Terra Sabaea">Terra Sabaea</a></li> <li><a href="/wiki/Tharsis" title="Tharsis">Tharsis</a></li> <li><a href="/wiki/List_of_extraterrestrial_dune_fields" title="List of extraterrestrial dune fields">Undae</a></li> <li><a href="/wiki/Mars_Polar_Lander#Landing_zone" title="Mars Polar Lander">Ultimi Scopuli</a></li> <li><a href="/wiki/Vastitas_Borealis" title="Vastitas Borealis">Vastitas Borealis</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Common_surface_features_of_Mars" title="Common surface features of Mars">Physical<br />features</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Martian_canals" title="Martian canals">"Canals"</a> (<a href="/wiki/List_of_Martian_canals" title="List of Martian canals">list</a>)</li> <li><a href="/wiki/Chasma#Mars" title="Chasma">Canyons</a></li> <li><a href="/wiki/Crater_chain" title="Crater chain">Catenae</a></li> <li><a href="/wiki/Chaos_terrain" title="Chaos terrain">Chaos terrain</a></li> <li><a href="/wiki/List_of_craters_on_Mars" title="List of craters on Mars">Craters</a></li> <li><a href="/wiki/Fossa_(planetary_nomenclature)" title="Fossa (planetary nomenclature)">Fossae</a></li> <li><a href="/wiki/Gullies_on_Mars" title="Gullies on Mars">Gullies</a></li> <li><a href="/wiki/Mensa_(geology)" title="Mensa (geology)">Mensae</a></li> <li><a href="/wiki/Planetary_nomenclature#Descriptor_terms_(feature_types)" title="Planetary nomenclature">Labyrinthi</a></li> <li><a href="/wiki/List_of_mountains_on_Mars" title="List of mountains on Mars">Mountains</a> <ul><li><a href="/wiki/List_of_mountains_on_Mars" title="List of mountains on Mars">by height</a></li></ul></li> <li><a href="/wiki/List_of_rocks_on_Mars" title="List of rocks on Mars">Observed rocks</a></li> <li><a href="/wiki/Outflow_channels" title="Outflow channels">Outflow channels</a></li> <li><a href="/wiki/List_of_plains_on_Mars" title="List of plains on Mars">Plains</a></li> <li><a href="/wiki/Valley_network_(Mars)" title="Valley network (Mars)">Valley network</a></li> <li><a href="/wiki/Vallis_(planetary_geology)" title="Vallis (planetary geology)">Valleys</a></li> <li><a href="/wiki/Gravity_of_Mars" title="Gravity of Mars">Gravity</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Geology_of_Mars" title="Geology of Mars">Geology</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Brain_terrain" title="Brain terrain">Brain terrain</a></li> <li><a href="/wiki/Carbonates_on_Mars" title="Carbonates on Mars">Carbonates</a></li> <li><a href="/wiki/List_of_areas_of_chaos_terrain_on_Mars" title="List of areas of chaos terrain on Mars">Chaos terrain</a></li> <li><a href="/wiki/Mars_surface_color" title="Mars surface color">Color</a></li> <li><a href="/wiki/Composition_of_Mars" title="Composition of Mars">Composition</a></li> <li><a href="/wiki/Concentric_crater_fill" title="Concentric crater fill">Concentric crater fill</a></li> <li><a href="/wiki/Dark_slope_streak" title="Dark slope streak">Dark slope streak</a></li> <li><a href="/wiki/Martian_dichotomy" title="Martian dichotomy">Dichotomy</a></li> <li><a href="/wiki/Fretted_terrain" title="Fretted terrain">Fretted terrain</a></li> <li><a href="/wiki/Geysers_on_Mars" title="Geysers on Mars">Geysers</a></li> <li><a href="/wiki/Glaciers_on_Mars" title="Glaciers on Mars">Glaciers</a></li> <li><a href="/wiki/Groundwater_on_Mars" title="Groundwater on Mars">Groundwater</a></li> <li><a href="/wiki/Gullies_on_Mars" title="Gullies on Mars">Gullies</a></li> <li><a href="/wiki/Lakes_on_Mars" title="Lakes on Mars">Lakes</a></li> <li><a href="/wiki/Martian_lava_tube" title="Martian lava tube">Lava tubes</a></li> <li><a href="/wiki/Lobate_debris_apron" title="Lobate debris apron">Lobate debris apron</a></li> <li><a href="/wiki/Marsquake" title="Marsquake">Marsquake</a></li> <li><a href="/wiki/Martian_meteorite" title="Martian meteorite">Meteorites</a> <ul><li><a href="/wiki/List_of_Martian_meteorites" title="List of Martian meteorites">on Earth</a></li> <li><a href="/wiki/List_of_rocks_on_Mars" title="List of rocks on Mars">on Mars</a></li></ul></li> <li><a href="/wiki/Mud_cracks_on_Mars" title="Mud cracks on Mars">Mud cracks</a></li> <li><a href="/wiki/North_Polar_Basin_(Mars)" title="North Polar Basin (Mars)">North Polar Basin</a></li> <li><a href="/wiki/Mars_ocean_theory" title="Mars ocean theory">Ocean theory</a></li> <li><a href="/wiki/Ore_resources_on_Mars" title="Ore resources on Mars">Ore resources</a></li> <li><a href="/wiki/Martian_polar_ice_caps" title="Martian polar ice caps">Polar caps</a> <ul><li><a href="/wiki/True_polar_wander_on_Mars" title="True polar wander on Mars">polar wander</a></li></ul></li> <li><a href="/wiki/Seasonal_flows_on_warm_Martian_slopes" title="Seasonal flows on warm Martian slopes">Recurring slope lineae (RSL)</a></li> <li><a href="/wiki/Ring_mold_crater" title="Ring mold crater">Ring mold craters</a></li> <li><a href="/wiki/Rootless_cone" title="Rootless cone">Rootless cones</a></li> <li><a href="/wiki/Seasonal_flows_on_warm_Martian_slopes" title="Seasonal flows on warm Martian slopes">Seasonal flows</a></li> <li><a href="/wiki/Martian_regolith" title="Martian regolith">Soil</a></li> <li><a href="/wiki/Martian_spherules" title="Martian spherules">Spherules</a></li> <li><a href="/wiki/Martian_surface" title="Martian surface">Surface</a></li> <li><a href="/wiki/Swiss_cheese_features" title="Swiss cheese features">"Swiss cheese" feature</a></li> <li><a href="/wiki/Terrain_softening" title="Terrain softening">Terrain softening</a></li> <li><a href="/wiki/Tharsis#Location_and_Size" title="Tharsis">Tharsis bulge</a></li> <li><a href="/wiki/Volcanism_on_Mars" title="Volcanism on Mars">Volcanism</a></li> <li><a href="/wiki/Water_on_Mars" title="Water on Mars">Water</a></li> <li><a href="/wiki/Yardangs_on_Mars" title="Yardangs on Mars">Yardangs</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Geological_history_of_Mars" title="Geological history of Mars">History</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Amazonian_(Mars)" title="Amazonian (Mars)">Amazonian</a></li> <li><a href="/wiki/Hesperian" title="Hesperian">Hesperian</a></li> <li><a href="/wiki/Noachian" title="Noachian">Noachian</a></li> <li><a href="/wiki/History_of_Mars_observation" title="History of Mars observation">Observation history</a></li> <li><a href="/wiki/Classical_albedo_features_on_Mars" title="Classical albedo features on Mars">Classical albedo features</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Astronomy_on_Mars" title="Astronomy on Mars">Astronomy</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Moons_of_Mars" title="Moons of Mars">Moons</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Phobos_(moon)" title="Phobos (moon)">Phobos</a> <ul><li><a href="/wiki/Stickney_(crater)" title="Stickney (crater)">Stickney crater</a></li> <li><a href="/wiki/Limtoc" title="Limtoc">Limtoc crater</a></li> <li><a href="/wiki/Phobos_monolith" title="Phobos monolith">Monolith</a></li></ul></li> <li><a href="/wiki/Deimos_(moon)" title="Deimos (moon)">Deimos</a> <ul><li><a href="/wiki/Swift_(Deimian_crater)" title="Swift (Deimian crater)">Swift crater</a></li> <li><a href="/wiki/Voltaire_(crater)" title="Voltaire (crater)">Voltaire crater</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Astronomical_transit" title="Astronomical transit">Transits</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Solar_eclipses_on_Mars" title="Solar eclipses on Mars">Solar eclipses on Mars</a></li> <li>Satellite transits <ul><li><a href="/wiki/Transit_of_Phobos_from_Mars" title="Transit of Phobos from Mars">Phobos</a></li> <li><a href="/wiki/Transit_of_Deimos_from_Mars" title="Transit of Deimos from Mars">Deimos</a></li></ul></li> <li>Planetary transits <ul><li><a href="/wiki/Transit_of_Earth_from_Mars" title="Transit of Earth from Mars">Earth</a></li> <li><a href="/wiki/Transit_of_Mercury_from_Mars" title="Transit of Mercury from Mars">Mercury</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Asteroid" title="Asteroid">Asteroids</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Impact_events_on_Mars" title="Impact events on Mars">Impacts</a></li> <li><a href="/wiki/List_of_Mars-crossing_minor_planets" title="List of Mars-crossing minor planets">Mars-crossers</a> <ul><li><span class="nowrap"><a href="/wiki/2007_WD5" title="2007 WD5">2007 WD<span style="position: relative; top: 0.3em;"><span style="font-size:80%;">5</span></span></a></span></li></ul></li> <li><a href="/wiki/Mars_trojan" title="Mars trojan">Trojans</a> <ul><li><a href="/wiki/5261_Eureka" title="5261 Eureka">5261 Eureka</a></li> <li><span class="nowrap"><a href="/wiki/(101429)_1998_VF31" title="(101429) 1998 VF31">1998 VF<sub>31</sub></a></span></li> <li><span class="nowrap"><a href="/wiki/(121514)_1999_UJ7" title="(121514) 1999 UJ7">1999 UJ<sub>7</sub></a></span></li> <li><span class="nowrap"><a href="/wiki/(311999)_2007_NS2" title="(311999) 2007 NS2">2007 NS<sub>2</sub></a></span></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Comets</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/C/2013_A1_(Siding_Spring)" title="C/2013 A1 (Siding Spring)">C/2013 A1 (Siding Spring)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">General</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Orbit_of_Mars" title="Orbit of Mars">Orbit</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Exploration_of_Mars" title="Exploration of Mars">Exploration</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%">Concepts</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Mars_flyby" title="Mars flyby">Flyby</a></li> <li><a href="/wiki/List_of_Mars_orbiters" title="List of Mars orbiters">Orbiter</a></li> <li><a href="/wiki/Mars_landing" title="Mars landing">Landing</a></li> <li><a href="/wiki/Mars_rover" title="Mars rover">Rover</a></li> <li><a href="/wiki/Mars_sample-return_mission" title="Mars sample-return mission">Sample return</a></li> <li><a href="/wiki/Human_mission_to_Mars" title="Human mission to Mars">Human mission</a></li> <li><a href="/wiki/Mars_to_Stay" title="Mars to Stay">Permanent settlement</a></li> <li><a href="/wiki/Colonization_of_Mars" title="Colonization of Mars">Colonization</a></li> <li><a href="/wiki/Terraforming_of_Mars" title="Terraforming of Mars">Terraforming</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Template:Mars_spacecraft" title="Template:Mars spacecraft">Missions</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/List_of_missions_to_Mars" title="List of missions to Mars">List of missions to Mars</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Advocacy</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><i><a href="/wiki/The_Mars_Project" title="The Mars Project">The Mars Project</a></i></li> <li><i><a href="/wiki/The_Case_for_Mars" title="The Case for Mars">The Case for Mars</a></i></li> <li><a href="/wiki/Inspiration_Mars_Foundation" title="Inspiration Mars Foundation">Inspiration Mars Foundation</a></li> <li><a href="/wiki/Mars_Institute" title="Mars Institute">Mars Institute</a></li> <li><a href="/wiki/Mars_Society" title="Mars Society">Mars Society</a></li> <li><a href="/wiki/Mars_race" title="Mars race">Mars race</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Related</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/List_of_artificial_objects_on_Mars" title="List of artificial objects on Mars">Artificial objects on Mars</a> <ul><li><a href="/wiki/List_of_extraterrestrial_memorials#Mars" title="List of extraterrestrial memorials">Memorials on Mars</a></li></ul></li> <li><a href="/wiki/Mars_in_fiction" title="Mars in fiction">Fiction</a> <ul><li><a href="/wiki/List_of_films_set_on_Mars" title="List of films set on Mars">List of films set on Mars</a></li> <li><a href="/wiki/Martian_scientist" title="Martian scientist">Martian scientist</a></li> <li><a href="/wiki/Mars_(mythology)" title="Mars (mythology)">Mythology</a></li></ul></li> <li><a href="/wiki/Flag_of_Mars" title="Flag of Mars">Flag of Mars</a></li> <li><a href="/wiki/Life_on_Mars" title="Life on Mars">Life on Mars</a></li> <li><a href="/wiki/Sub-Earth" title="Sub-Earth">Sub-Earth</a></li> <li><a href="/wiki/Timekeeping_on_Mars" title="Timekeeping on Mars">Timekeeping on Mars</a> <ul><li><a href="/wiki/Mars_sol" title="Mars sol">Sol (day on Mars)</a></li> <li><a href="/wiki/Darian_calendar" title="Darian calendar">Darian calendar</a></li></ul></li></ul> 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