{"id":783,"date":"2011-01-25T15:27:00","date_gmt":"2011-01-25T14:27:00","guid":{"rendered":"https:\/\/kids.esa.int\/moons\/"},"modified":"2026-10-08T00:32:12","modified_gmt":"2026-10-07T22:32:12","slug":"moons","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/moons\/","title":{"rendered":"Les lunes"},"content":{"rendered":"
\n

Les lunes sont des objets naturels qui gravitent autour des plan\u00e8tes. Les scientifiques les qualifient souvent de \u00absatellites des plan\u00e8tes\u00bb (les satellites fabriqu\u00e9s par l\u2019homme sont parfois appel\u00e9s \u00ablunes artificielles\u00bb). Notre syst\u00e8me solaire compte pr\u00e8s de 170 lunes. La plupart d\u2019entre elles orbitent autour des g\u00e9ants de gaz que sont Jupiter et Saturne. Les petites plan\u00e8tes ont en g\u00e9n\u00e9ral peu de lunes: Mars en a deux, la Terre une seule, tandis que Venus et Mercure n\u2019en ont aucune.<\/p>\n<\/div>\n

La Lune de la Terre est exceptionnellement grosse par rapport \u00e0 la taille de notre plan\u00e8te. Les lunes sont g\u00e9n\u00e9ralement \u00e9clips\u00e9es par leur plan\u00e8te avoisinante. Cependant, certaines des lunes de Jupiter et de Saturne sont beaucoup plus grosses que notre Lune. Ganymede et Titan sont plus grosses que la plan\u00e8te Mercure.<\/p>\n

En raison de leur petite taille, presque toutes les lunes sont incapables de retenir l\u2019atmosph\u00e8re. Leur faible gravit\u00e9 permet aux gaz de s\u2019\u00e9chapper dans l\u2019espace. Titan, la plus grosse lune de Saturne, fait exception \u00e0 cette r\u00e8gle. Titan a une atmosph\u00e8re plus \u00e9paisse et plus dense que la Terre. L\u2019azote est le principal gaz pr\u00e9sent dans les deux atmosph\u00e8res, mais Titan n\u2019a pas d\u2019oxyg\u00e8ne, ni de vie. Sa surface est masqu\u00e9e par un nuage orange. Certaines scientifiques consid\u00e8rent Titan comme une Terre primitive prise dans un gel profond.<\/p>\n

D\u2019aucuns pensent que certaines satellites, y compris notre Lune, seraient n\u00e9s durant les collisions qui se sont produites au d\u00e9but de l\u2019histoire de notre syst\u00e8me solaire. La Lune se serait form\u00e9e \u00e0 partir du nuage de d\u00e9bris rest\u00e9 en orbite autour de la Terre. D\u2019autres ont pu se former \u00e0 partir d\u2019un nuage de gaz et de poussi\u00e8res qui entourait les plan\u00e8tes g\u00e9antes alors qu\u2019elles attiraient la mati\u00e8re vers elles. La plupart des petites lunes sont des com\u00e8tes ou des ast\u00e9ro\u00efdes qui ont \u00e9t\u00e9 captur\u00e9s au moment de leur passage \u00e0 proximit\u00e9 d\u2019une grosse plan\u00e8te.<\/p>","protected":false},"excerpt":{"rendered":"

Moons are natural objects that orbit planets. Scientists usually refer to them as planetary satellites (human-made satellites are sometimes called artificial moons). There are about 170 moons in our Solar […]<\/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\/2008\/04\/five_saturn_moons2\/17883435-2-eng-GB\/Five_Saturn_moons.jpg","esa_banner_description":"","esa_banner_credit":"NASA \/ JPL","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2008\/04\/Five_Saturn_moons2","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-783","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\/783","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=783"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/783\/revisions"}],"predecessor-version":[{"id":1926,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/783\/revisions\/1926"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=783"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=783"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=783"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=783"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=783"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=783"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=783"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=783"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=783"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=783"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}