{"id":879,"date":"2006-07-27T09:13:00","date_gmt":"2006-07-27T07:13:00","guid":{"rendered":"https:\/\/kids.esa.int\/methane_lakes_and_ice_pebbles\/"},"modified":"2026-10-08T00:33:18","modified_gmt":"2026-10-07T22:33:18","slug":"methane_lakes_and_ice_pebbles","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/methane_lakes_and_ice_pebbles\/","title":{"rendered":"Lacs de m\u00e9thane et galets de glace"},"content":{"rendered":"
\n

Titan, la lune de Saturne, est l'un des plus gros et des plus fascinants satellites du syst\u00e8me solaire. Malheureusement, sa surface est cach\u00e9e sous une \u00e9paisse couche de brume orang\u00e9e. R\u00e9cemment encore, personne ne savait \u00e0 quoi ressemblait la surface de Titan.<\/p>\n<\/div>\n

Un instrument radar de la sonde spatiale Cassini de la NASA a permis de percer cette couche brumeuse. Les signaux radio envoy\u00e9s par Cassini traversent l'\u00e9pais nuage et rebondissent \u00e0 la surface. L'analyse de ces \u00e9chos a permis aux chercheurs de d\u00e9celer la pr\u00e9sence de nombreuses taches brunes. Certaines d'entre elles rejoignent d'\u00e9troits canaux sinueux \u2013 possiblement des rivi\u00e8res.<\/p>\n

Il semblerait que les zones sombres et lisses apparaissant sur les images radar soient des lacs. Et pourtant la temp\u00e9rature de la surface de Titan est de -180\u00b0C, il est donc impossible que ces lacs contiennent de l'eau. Il semblerait plut\u00f4t qu'ils contiennent du m\u00e9thane ou de l'\u00e9thane liquide. (Sur Terre, le gaz de m\u00e9thane est utilis\u00e9 dans les chaudi\u00e8res et les cuisini\u00e8res.)<\/p>\n

\"First
Premi\u00e8re image en couleur de la surface de Titan<\/figcaption><\/figure>\n

Beaucoup avaient esp\u00e9r\u00e9 que la sonde Huygens de l'ESA ferait un plongeon dans un lac de m\u00e9thane pendant sa descente vers la surface de Titan le 14 janvier 2005. Cependant, les images prises par sa cam\u00e9ra n'ont r\u00e9v\u00e9l\u00e9 qu'une plaine tarie recouverte de galets de glace.<\/p>\n

Depuis ce succ\u00e8s spectaculaire, les chercheurs ont trouv\u00e9 un moyen d'en savoir plus sur l'environnement de Huygens, gr\u00e2ce \u00e0 un mod\u00e8le de mont\u00e9e et de descente inhabituel des signaux radio envoy\u00e9s par Huygens \u00e0 Cassini. En effet, une partie des signaux ne se dirigeait pas directement vers Cassini mais rebondissait \u00e0 la surface. L'analyse du signal a permis d'\u00e9tablir que la surface est relativement plate dans un p\u00e9rim\u00e8tre de 2 km de la sonde. Ce lac sec est recouvert essentiellement de galets de glace mesurant environ environ 5-10 cm.<\/p>","protected":false},"excerpt":{"rendered":"

Saturn\u2019s moon Titan is one of the largest and most fascinating satellites in the Solar System. Unfortunately, its surface is hidden beneath a thick blanket of orange cloud. Until recently, […]<\/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\/2006\/07\/lakes_on_titan2\/18249176-2-eng-GB\/Lakes_on_Titan.jpg","esa_banner_description":"Lakes on Titan","esa_banner_credit":"NASA\/JPL","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2006\/07\/Lakes_on_Titan2","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":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-879","post","type-post","status-publish","format-standard","hentry","category-learn","category-our-universe","category-planets-and-moons"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/879","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=879"}],"version-history":[{"count":5,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/879\/revisions"}],"predecessor-version":[{"id":4716,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/879\/revisions\/4716"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=879"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=879"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=879"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=879"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=879"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=879"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=879"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=879"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=879"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=879"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}