{"id":822,"date":"2004-12-02T15:38:00","date_gmt":"2004-12-02T14:38:00","guid":{"rendered":"https:\/\/kids.esa.int\/different_orbits\/"},"modified":"2026-10-08T00:32:40","modified_gmt":"2026-10-07T22:32:40","slug":"different_orbits","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/different_orbits\/","title":{"rendered":"Diff\u00e9rentes orbites"},"content":{"rendered":"<div class=\"lede\">\n<p>Une orbite est la trajectoire suivie par un objet autour d'un point pr\u00e9cis dans l'espace, par exemple la trajectoire de la Lune autour de la Terre. Les orbites sont d\u00e9termin\u00e9es par la gravit\u00e9 et sont souvent \u2018 elliptiques \u2019, c'est-\u00e0-dire de forme ovale.<\/p>\n<\/div>\n<p>Chaque satellite est plac\u00e9 sur l\u2019orbite qui convient le mieux \u00e0 sa mission. Par exemple, les satellites d\u2019observation de la Terre sont en g\u00e9n\u00e9ral plac\u00e9s sur des orbites circulaires basses (400 \u2013 1,200 km). Ceci leur permet de faire le tour complet de la Terre en quelques heures et d\u2019acqu\u00e9rir des images d\u00e9taill\u00e9es de la surface terrestre.<\/p>\n<p>La meilleure trajectoire pour ces satellites est une orbite \u201c polaire \u201d, qui les fait passer au-dessus des p\u00f4les Nord et Sud. Alors que la Terre tourne sous eux, les satellites peuvent observer directement vers le bas et \u00e9tudier l'ensemble de la plan\u00e8te \u2013 bande par bande \u2013 sur une p\u00e9riode de quelques jours.<\/p>\n<p>Les satellites m\u00e9t\u00e9orologiques et de communication 'restent' souvent au dessus de la m\u00eame partie de la Terre 24h sur 24. Pour ce faire, ils sont plac\u00e9s en orbite circulaire environ 36 000 km au dessus de l\u2019Equateur. A cette altitude, ils se d\u00e9placent \u00e0 la m\u00eame vitesse que celle de la rotation de la Terre et observent donc toujours les m\u00eames endroits. C\u2019est ce qu\u2019on appelle une 'orbite g\u00e9ostationnaire'.<\/p>\n<p>Un certain nombre de satellites scientifiques, comme les Cluster de l\u2019ESA et XMM-Newton, d\u00e9crivent des orbites tr\u00e8s elliptiques (en forme d\u2019\u0153uf) qui les rapprochent beaucoup de la Terre puis les en \u00e9loignent ensuite consid\u00e9rablement.<\/p>","protected":false},"excerpt":{"rendered":"<p>An orbit is the path of an object around a particular point in space, for example the path the Moon takes around the Earth. Orbits are determined by gravity, and [&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\/2001\/05\/some_popular_orbits3\/17864898-3-eng-GB\/Some_popular_orbits.jpg","esa_banner_description":"Some popular orbits","esa_banner_credit":"ESA","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2001\/05\/Some_popular_orbits3","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":[10,65,40],"tags":[2],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-822","post","type-post","status-publish","format-standard","hentry","category-learn","category-mission-control","category-technology","tag-background-article"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/822","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=822"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/822\/revisions"}],"predecessor-version":[{"id":1965,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/822\/revisions\/1965"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=822"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=822"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=822"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=822"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=822"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=822"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=822"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=822"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=822"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=822"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}