{"id":900,"date":"2008-12-15T09:35:00","date_gmt":"2008-12-15T08:35:00","guid":{"rendered":"https:\/\/kids.esa.int\/life_on_extrasolar_planets\/"},"modified":"2026-10-08T00:33:33","modified_gmt":"2026-10-07T22:33:33","slug":"life_on_extrasolar_planets","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/life_on_extrasolar_planets\/","title":{"rendered":"La vie sur les exoplan\u00e8tes"},"content":{"rendered":"
\n

En 2008, le t\u00e9lescope spatial Hubble, d\u00e9velopp\u00e9 conjointement par la NASA et l\u2019ESA, a \u00e9tabli la pr\u00e9sence de dioxyde de carbone dans l\u2019atmosph\u00e8re d\u2019une plan\u00e8te de la taille de Jupiter orbitant autour d\u2019une autre \u00e9toile. Cet \u00e9l\u00e9ment \u00e9tait consid\u00e9r\u00e9 comme un grand pas dans la recherche de preuves de vie dans d\u2019autres mondes.<\/p>\n<\/div>\n

Quelque 300 plan\u00e8tes ont, jusque-l\u00e0, \u00e9t\u00e9 d\u00e9couvertes en orbite autour d'\u00e9toiles distantes. Malheureusement, ces exoplan\u00e8tes sont de si faible luminosit\u00e9 et si \u00e9loign\u00e9es qu'il est extr\u00eamement difficile de les \u00e9tudier. Cependant, gr\u00e2ce aux instruments sophistiqu\u00e9s d'aujourd'hui, les scientifiques commencent peu \u00e0 peu \u00e0 en savoir plus sur ces mondes extra-terrestres et les gaz qui composent leur atmosph\u00e8re.<\/p>\n

Le dioxyde de carbone est le gaz que les plantes recrachent la nuit et qui leur permet de pousser. Les animaux et les humains le recrachent en permanence. Etant l'un des principaux gaz \u00e0 effet de serre, il retient la chaleur et aide \u00e0 chauffer la plan\u00e8te. Les compos\u00e9s organiques, les ingr\u00e9dients de base pour la vie, sont essentiellement constitu\u00e9s de carbone. Et voil\u00e0 que Hubble vient de d\u00e9montrer que nous pouvions d\u00e9tecter le dioxyde de carbone sur les plan\u00e8tes \u00e9loign\u00e9es et avoir une id\u00e9e de la quantit\u00e9. C'est une avanc\u00e9e consid\u00e9rable dans notre effort \u00e0 long terme visant \u00e0 savoir de quoi sont faits ces mondes et s'ils sont viables.<\/p>\n

La plan\u00e8te, appel\u00e9e HD 189733b, est trop chaude pour pouvoir vivre dessus. Mais c'est une plan\u00e8te qui vaut d'\u00eatre observ\u00e9e car elle dispara\u00eet derri\u00e8re son \u00e9toile compagnon tous les 2,2 jours. En \u00e9tudiant les changements r\u00e9guliers survenant dans la lumi\u00e8re qui arrive sur Terre, les scientifiques peuvent analyser l'atmosph\u00e8re de la plan\u00e8te. Plus t\u00f4t cette ann\u00e9e, Hubble avait d\u00e9j\u00e0 d\u00e9couvert de la vapeur d'eau et du m\u00e9thane sur cette plan\u00e8te. Les nouvelles d\u00e9couvertes de Hubble prouvent que les \u00e9l\u00e9ments \u00e9l\u00e9mentaires de la vie peuvent \u00eatre mesur\u00e9s sur les plan\u00e8tes orbitant autour d'autres \u00e9toiles.<\/p>","protected":false},"excerpt":{"rendered":"

In 2008, the NASA\/ESA Hubble Space Telescope discovered carbon dioxide in the atmosphere of a Jupiter-sized planet orbiting another star. This was seen as an important step in the search […]<\/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\/12\/hd_189733b2\/18246735-2-eng-GB\/HD_189733b.jpg","esa_banner_description":"HD 189733b","esa_banner_credit":"ESA, NASA, M. Kornmesser (ESA\/Hubble) and STScI","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2008\/12\/HD_189733b2","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":[14,10,13],"tags":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-900","post","type-post","status-publish","format-standard","hentry","category-are-we-alone","category-learn","category-life-in-space"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/900","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=900"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/900\/revisions"}],"predecessor-version":[{"id":2043,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/900\/revisions\/2043"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=900"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=900"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=900"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=900"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=900"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=900"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=900"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=900"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=900"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=900"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}