{"id":395,"date":"2018-04-16T12:39:00","date_gmt":"2018-04-16T10:39:00","guid":{"rendered":"https:\/\/kids.esa.int\/esa_satellites_map_mysterious_ocean_magnetism\/"},"modified":"2026-10-08T00:27:41","modified_gmt":"2026-10-07T22:27:41","slug":"esa_satellites_map_mysterious_ocean_magnetism","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/esa_satellites_map_mysterious_ocean_magnetism\/","title":{"rendered":"Des satellites de l\u2019ESA cartographient le myst\u00e9rieux magn\u00e9tisme des oc\u00e9ans"},"content":{"rendered":"<div class=\"lede\">\n<p>Notre plan\u00e8te est fascinante, mais elle rec\u00e8le encore bien des myst\u00e8res. Une mission de l\u2019ESA baptis\u00e9e Swarm devrait nous aider \u00e0 mieux comprendre le champ magn\u00e9tique de la Terre, qui intrigue encore la communaut\u00e9 scientifique. La mission Swarm est compos\u00e9e de trois satellites. Leurs derniers r\u00e9sultats viennent d\u2019\u00eatre d\u00e9voil\u00e9s!<\/p>\n<\/div>\n<figure class=\"wp-block-image size-large\" data-width=\"5209\" data-credit=\"ESA\/ATG medialab\" data-detail-url=\"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2018\/04\/Earth_s_protective_shield\" 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\/2018\/04\/earth_s_protective_shield\/17902049-2-eng-GB\/Earth_s_protective_shield.jpg\" alt=\"Earth&#x27;s protective shield\"><figcaption>Le bouclier protecteur de la Terre<\/figcaption><\/figure>\n<p>Le champ magn\u00e9tique terrestre est principalement g\u00e9n\u00e9r\u00e9 par du fer liquide extr\u00eamement chaud qui circule au c\u0153ur de notre plan\u00e8te. Les roches magn\u00e9tis\u00e9es de la cro\u00fbte terrestre jouent \u00e9galement un r\u00f4le mineur. Saviez-vous que l\u2019eau de mer est \u00e9galement une source de magn\u00e9tisme ? Lorsque l\u2019eau de mer sal\u00e9e traverse le champ magn\u00e9tique terrestre, un courant \u00e9lectrique est g\u00e9n\u00e9r\u00e9, ce qui cr\u00e9e \u00e0 son tour une force magn\u00e9tique. Celle-ci est tr\u00e8s faible et extr\u00eamement difficile \u00e0 mesurer, mais c\u2019est pr\u00e9cis\u00e9ment ce qu\u2019ont r\u00e9ussi \u00e0 faire les satellites Swarm.<\/p>\n<p>La cartographie des champs magn\u00e9tiques, de la surface de l\u2019oc\u00e9an jusqu\u2019aux fonds marins, a permis aux scientifiques de d\u00e9couvrir comment l\u2019eau circule \u00e0 toutes les profondeurs, ce qui constitue une information tout \u00e0 fait nouvelle. Les oc\u00e9ans absorbent la chaleur de l\u2019air ; le suivi de la mani\u00e8re dont cette chaleur se propage \u00e0 travers les oc\u00e9ans est donc un \u00e9l\u00e9ment essentiel pour mieux comprendre le climat terrestre. Les derniers r\u00e9sultats de la mission Swarm nous aident m\u00eame \u00e0 mieux conna\u00eetre les propri\u00e9t\u00e9s \u00e9lectriques de la cro\u00fbte terrestre et de la couche situ\u00e9e juste en dessous, appel\u00e9e lithosph\u00e8re. En effet, Swarm a \u00e9tabli une nouvelle carte du champ magn\u00e9tique g\u00e9n\u00e9r\u00e9 par la cro\u00fbte terrestre !<\/p>\n<\/p>\n<p>Swarm a observ\u00e9 l'\u00e9volution de notre champ magn\u00e9tique sur 24 heures. Les zones rouges mettent en \u00e9vidence les signaux magn\u00e9tiques les plus intenses. Copyright : \u00a9 Planetary Visions (cr\u00e9dits : ESA\/Planetary Visions).<\/p>\n<p>Tout cela est important car le champ magn\u00e9tique terrestre nous prot\u00e8ge des rayonnements nocifs provenant de l'espace, fait partie int\u00e9grante de notre climat et peut nous r\u00e9v\u00e9ler des secrets sur l'int\u00e9rieur de notre plan\u00e8te. Ainsi, plus nous en apprenons sur notre champ magn\u00e9tique, plus nous en savons sur notre plan\u00e8te.<\/p>\n<p><b>Fait int\u00e9ressant :<\/b> Les trois satellites Swarm s'appellent Alpha, Bravo et Charlie.<\/p>\n<figure class=\"wp-block-image size-large\" data-width=\"1680\" data-credit=\"Join ETH Zurich on a journey into space: Ulrike Kastrup, Kerstin Fankhauser, Gillian Gr\u00fcn, Jessica Kind, Bettina Gutbrodt, Andrea D\u00e4hler; focusTerra, ETH Z\u00fcrich; Illustrations by Astrid Nippoldt of Studio Nippoldt, 2018\" data-detail-url=\"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2018\/04\/Hunting_for_that_elusive_magnetic_signal\" 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\/2018\/04\/hunting_for_that_elusive_magnetic_signal\/17882104-2-eng-GB\/Hunting_for_that_elusive_magnetic_signal.jpg\" alt=\"Hunting for that elusive magnetic signal\"><figcaption>\u00c0 la recherche de ce signal magn\u00e9tique insaisissable<\/figcaption><\/figure>","protected":false},"excerpt":{"rendered":"<p>Planet Earth is a fascinating world, and there is still a lot about it that we do not fully understand. Earth\u2019s magnetic field intrigues scientists, and an ESA mission called [&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\/2018\/04\/front_of_swarm_satellite\/17879477-2-eng-GB\/Front_of_Swarm_satellite.jpg","esa_banner_description":"Front of Swarm satellite","esa_banner_credit":"ESA\/ATG medialab","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2018\/04\/Front_of_Swarm_satellite","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":[26],"tags":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-395","post","type-post","status-publish","format-standard","hentry","category-news"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/395","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=395"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/395\/revisions"}],"predecessor-version":[{"id":4441,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/395\/revisions\/4441"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=395"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=395"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=395"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=395"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=395"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=395"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=395"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=395"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=395"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=395"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}