{"id":1101,"date":"2005-12-09T13:07:00","date_gmt":"2005-12-09T12:07:00","guid":{"rendered":"https:\/\/kids.esa.int\/moons_and_rings\/"},"modified":"2026-10-08T00:36:01","modified_gmt":"2026-10-07T22:36:01","slug":"moons_and_rings","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/moons_and_rings\/","title":{"rendered":"Des lunes et des anneaux"},"content":{"rendered":"
\n

Toutes les plan\u00e8tes tournent autour du Soleil dans le sens inverse des aiguilles d\u2019une montre \u2013 vu depuis le p\u00f4le Nord de la Terre. Leur ann\u00e9e \u2013 c\u2019est-\u00e0-dire le temps qu\u2019elles mettent pour effectuer une orbite compl\u00e8te \u2013 varie en fonction de leur distance par rapport au Soleil. Une ann\u00e9e sur Mercure ne dure que 88 jours terrestres ; ainsi, une personne n\u00e9e l\u00e0-bas f\u00eaterait quatre fois plus d\u2019anniversaires que nous sur Terre. \u00c0 l\u2019inverse, une ann\u00e9e sur Pluton \u00e9quivaut \u00e0 248 de nos ann\u00e9es. Une personne n\u00e9e sur Pluton ne f\u00eaterait donc jamais son anniversaire !<\/p>\n<\/div>\n

Venus et Mercure n'ont pas de satellites naturels, mais les six autres plan\u00e8tes ont toutes des lunes autour d'elles. Jusqu'\u00e0 pr\u00e9sent, on en a d\u00e9nombr\u00e9 162. La plupart de ces lunes sont de tr\u00e8s petite taille et difficiles \u00e0 voir, m\u00eame avec de gros t\u00e9lescopes. A ce jour, Jupiter d\u00e9tient le record, avec 63 satellites connus, dont quatre sont de la taille d'une plan\u00e8te \u2013 Ganymede (le plus gros satellite du syst\u00e8me solaire), Callisto, Europa et Io.<\/p>\n

L'importante gravit\u00e9 des autres g\u00e9ants gazeux a \u00e9galement r\u00e9uni un grand nombre de satellites : Saturne en compte 56, Uranus 27 et Neptune 13. Autour de la Terre, gravite une seule grosse lune, tandis que Mars a deux minuscules compagnons. Quant aux \u201cplan\u00e8tes naines\u201d, Pluton a trois lunes (dont une relativement grosse) et Eris en a une.<\/p>\n

Les quatre plus grandes plan\u00e8tes \u2013 Jupiter, Saturne, Uranus et Neptune \u2013 poss\u00e8dent elles aussi des anneaux. Ceux-ci sont constitu\u00e9s de fragments de glace et de roche dont la taille varie de celle d\u2019une montagne \u00e0 celle d\u2019un nuage de fum\u00e9e de cigarette. Ces anneaux pourraient \u00eatre les vestiges d\u2019une lune qui se serait bris\u00e9e, ou des fragments arrach\u00e9s \u00e0 des lunes voisines.<\/p>","protected":false},"excerpt":{"rendered":"

All of the planets travel around the Sun in a counter-clockwise direction \u2013 as seen from above Earth\u2019s north pole. Their year – the time they take to complete one […]<\/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\/2005\/04\/jupiter_s_moon_europa2\/17905460-2-eng-GB\/Jupiter_s_moon_Europa.jpg","esa_banner_description":"Jupiter's moon, Europa","esa_banner_credit":"NASA\/DLR","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2005\/04\/Jupiter_s_moon_Europa2","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-1101","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\/1101","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=1101"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/1101\/revisions"}],"predecessor-version":[{"id":2244,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/1101\/revisions\/2244"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=1101"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=1101"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=1101"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=1101"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=1101"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=1101"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=1101"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=1101"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=1101"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=1101"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}