{"id":582,"date":"2010-10-27T08:10:00","date_gmt":"2010-10-27T06:10:00","guid":{"rendered":"https:\/\/kids.esa.int\/cluster_explores_invisible_space\/"},"modified":"2026-10-08T00:29:54","modified_gmt":"2026-10-07T22:29:54","slug":"cluster_explores_invisible_space","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/cluster_explores_invisible_space\/","title":{"rendered":"Cluster explore l\u2019espace invisible"},"content":{"rendered":"<div class=\"lede\">\n<p>Au cours de l\u2019\u00e9t\u00e9 2000, quatre satellites Cluster identiques ont \u00e9t\u00e9 lanc\u00e9s sur des orbites polaires fortement allong\u00e9es qui les ont emmen\u00e9s \u00e0 un tiers du trajet Terre-Lune. Depuis, le quatuor de l\u2019ESA, dont les membres s\u2019appellent Salsa, Samba, Rumba et Tango, vole en formation autour de la Terre. Il lui arrive de p\u00e9n\u00e9trer dans le champ magn\u00e9tique de notre plan\u00e8te. Parfois aussi, les sondes quittent la magn\u00e9tosph\u00e8re et volent \u00e0 travers les particules charg\u00e9es \u00e9lectriquement du vent solaire.<\/p>\n<\/div>\n<p>Leurs orbites et distances de s\u00e9paration ayant chang\u00e9, ces sondes nous ont fourni les premi\u00e8res observations en 3D des particules invisibles et des champs magn\u00e9tiques qui occupent l\u2019espace proche de la Terre. L\u2019un des ph\u00e9nom\u00e8nes les plus int\u00e9ressants est l\u2019aurore, un rideau de lumi\u00e8re rouge et vert que l\u2019on observe dans le ciel nocturne au-dessus des r\u00e9gions polaires. Les aurores se produisent lorsque des particules supersoniques en provenance du Soleil entrent en collision avec le champ magn\u00e9tique de notre plan\u00e8te. La plupart des particules sont d\u00e9vi\u00e9es par l\u2019\u00e9cran magn\u00e9tique de la Terre mais certaines passent \u00e0 travers et restent prises au pi\u00e8ge.<\/p>\n<figure class=\"wp-block-image size-natural\" data-width=\"400\" data-credit=\"NASA\/ ESA\" data-detail-url=\"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2009\/04\/Effect_of_extreme_solar_activity_on_Earth_s_magnetosphere2\" 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\/2009\/04\/effect_of_extreme_solar_activity_on_earth_s_magnetosphere2\/17908974-2-eng-GB\/Effect_of_extreme_solar_activity_on_Earth_s_magnetosphere.gif\" alt=\"Effect of extreme solar activity on Earth&#x27;s magnetosphere\"><figcaption>Effect of extreme solar activity on Earth&#x27;s magnetosphere<\/figcaption><\/figure>\n<p>Ces particules descendent alors en spirale le long des lignes du champ magn\u00e9tique et entrent en collision avec la haute atmosph\u00e8re, ce qui cr\u00e9e l\u2019aurore. Des \u00ab trous \u00bb sombres que l\u2019on appelle des aurores noires apparaissent parfois dans ce rideau color\u00e9. La mission Cluster a d\u00e9couvert que ceux-ci se produisent en des points o\u00f9 les particules s\u2019\u00e9chappent vers le haut en direction de l\u2019espace au lieu de descendre dans l\u2019atmosph\u00e8re.<\/p>\n<p>Cluster a de nombreuses autres d\u00e9couvertes \u00e0 son actif, notamment celle de tourbillons g\u00e9ants qui injectent des particules dans le champ magn\u00e9tique de la Terre. La mission a \u00e9galement r\u00e9v\u00e9l\u00e9 comment les \u00e9lectrons \u00ab tueurs \u00bb devenaient \u00e9nerg\u00e9tiques au point de pouvoir d\u00e9sactiver ou d\u00e9truire un satellite en orbite.<\/p>\n<p>Les quatre satellites ne sont plus tout jeunes mais l\u2019\u00e9quipe de Cluster estime qu\u2019ils pourront fonctionner jusqu'\u00e0 au moins 2012. Et jusqu\u2019alors, les scientifiques du monde entier esp\u00e8rent bien continuer \u00e0 explorer l\u2019espace invisible autour de la Terre.<\/p>","protected":false},"excerpt":{"rendered":"<p>In the summer of 2000, four identical Cluster spacecraft were launched into highly elongated polar orbits which took them one third of the way to the Moon. Since then, the [&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\/2000\/08\/the_four_cluster_spacecraft2\/17866490-3-eng-GB\/The_four_Cluster_spacecraft.jpg","esa_banner_description":"The four Cluster spacecraft","esa_banner_credit":"ESA","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2000\/08\/The_four_Cluster_spacecraft2","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":[10,11,35],"tags":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-582","post","type-post","status-publish","format-standard","hentry","category-learn","category-our-universe","category-the-sun"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/582","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=582"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/582\/revisions"}],"predecessor-version":[{"id":4561,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/582\/revisions\/4561"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=582"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=582"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=582"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=582"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=582"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=582"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=582"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=582"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=582"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=582"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}