{"id":887,"date":"2007-03-16T12:23:00","date_gmt":"2007-03-16T11:23:00","guid":{"rendered":"https:\/\/kids.esa.int\/radar_s_icy_echoes_on_mars\/"},"modified":"2026-10-08T00:33:23","modified_gmt":"2026-10-07T22:33:23","slug":"radar_s_icy_echoes_on_mars","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/radar_s_icy_echoes_on_mars\/","title":{"rendered":"Echos radar \u00ab glac\u00e9s \u00bb sur Mars"},"content":{"rendered":"<div class=\"lede\">\n<p>La plan\u00e8te Mars est souvent consid\u00e9r\u00e9e comme un monde aride recouvert de d\u00e9serts. Cependant, tout comme la Terre, la plan\u00e8te rouge compte deux grandes calottes glaciaires au niveau de ses p\u00f4les nord et sud. Pour pouvoir envisager une vie humaine sur Mars, il est important de conna\u00eetre la quantit\u00e9 d'eau glac\u00e9e contenue dans ces calottes polaires. C'est justement ce que l'instrument MARSIS embarqu\u00e9 sur l'orbiteur Mars Express de l'ESA est en train de d\u00e9couvrir.<\/p>\n<\/div>\n<p>Pour mesurer l'\u00e9paisseur de la couche de glace septentrionale, l'instrument radar envoie des signaux invisibles vers la surface et enregistre les \u00e9chos. Le radar est ainsi en mesure de \u00ab voir \u00bb \u00e0 travers les couches jusqu'\u00e0 la limite inf\u00e9rieure de la glace. Plus de 300 de ces \u00ab coupes \u00bb ont \u00e9t\u00e9 r\u00e9alis\u00e9es \u00e0 travers les d\u00e9p\u00f4ts de glace et de poussi\u00e8re recouvrant le p\u00f4le.<\/p>\n<figure class=\"wp-block-image size-large\" data-width=\"2369\" data-credit=\"NASA\/JPL\/ASI\/ESA\/Univ. of Rome\/MOLA Science Team\/USGS\" data-detail-url=\"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2007\/03\/Thickness_of_Mars_South_Polar_Layered_Deposits2\" data-licence=\"ESA Standard Licence\" data-licence-url=\"https:\/\/www.esa.int\/ESA_Multimedia\/Terms_and_conditions_of_use_of_images_and_videos_available_on_the_esa_website\"><img decoding=\"async\" loading=\"lazy\" style=\"max-width:100%;height:auto\" src=\"https:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2007\/03\/thickness_of_mars_south_polar_layered_deposits2\/17892316-2-eng-GB\/Thickness_of_Mars_South_Polar_Layered_Deposits.jpg\" alt=\"Thickness of Mars&#x27; South Polar Layered Deposits\"><figcaption>\u00c9paisseur des d\u00e9p\u00f4ts stratifi\u00e9s du p\u00f4le sud de Mars<\/figcaption><\/figure>\n<p>Nous savons maintenant que l'\u00e9paisseur de la calotte septentrionale est de 3,7 km environ. Si toute cette glace fondait, la plan\u00e8te enti\u00e8re serait recouverte par un oc\u00e9an de pr\u00e8s de 11 m\u00e8tres de profondeur. La roche sur laquelle repose cette massive couche de glace ne s'est pas affaiss\u00e9e sous le poids de cette derni\u00e8re, ce qui prouve que sa rigidit\u00e9 est sup\u00e9rieure \u00e0 celle de la cro\u00fbte terrestre.<\/p>\n<p>Les \u00e9tudes radar en cours ont d\u00e9montr\u00e9 que la calotte polaire nord avait une \u00e9paisseur d'environ 1,8 km. Les fines couches de glace hydrique et de poussi\u00e8re observ\u00e9es au niveau des deux p\u00f4les semblent \u00eatre provoqu\u00e9es par des changements climatiques saisonniers et \u00e0 long terme. Bien que les calottes polaires concentrent la plus grande partie de l'eau d\u00e9couverte sur la plan\u00e8te Mars moderne, il est possible que d'autres zones de la plan\u00e8te aient \u00e9t\u00e9 suffisamment humides pour permettre la vie dans un pass\u00e9 lointain.<\/p>","protected":false},"excerpt":{"rendered":"<p>Mars is often regarded as an arid world covered by deserts. However, like Earth, the Red Planet has two large ice caps at its north and south poles. If people [&hellip;]<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"esa_banner_image":"https:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2007\/03\/bright_lower_echo_from_mars_south-polar_layered_deposits2\/17901975-2-eng-GB\/Bright_lower_echo_from_Mars_south-polar_layered_deposits.jpg","esa_banner_description":"Bright lower echo from Mars\u2019 south-polar layered deposits","esa_banner_credit":"NASA\/JPL\/ASI\/ESA\/Univ. of Rome\/MOLA Science Team","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2007\/03\/Bright_lower_echo_from_Mars_south-polar_layered_deposits2","esa_external_url":"","esa_external_new_window":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":true},"categories":[10,11,12],"tags":[2],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-887","post","type-post","status-publish","format-standard","hentry","category-learn","category-our-universe","category-planets-and-moons","tag-background-article"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/887","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/comments?post=887"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/887\/revisions"}],"predecessor-version":[{"id":4723,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/887\/revisions\/4723"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=887"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=887"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=887"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=887"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=887"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=887"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=887"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=887"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=887"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=887"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}