{"id":1142,"date":"2004-11-19T08:27:00","date_gmt":"2004-11-19T07:27:00","guid":{"rendered":"https:\/\/kids.esa.int\/are_we_alone_life_on_earth\/"},"modified":"2026-10-08T00:36:29","modified_gmt":"2026-10-07T22:36:29","slug":"are_we_alone_life_on_earth","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/are_we_alone_life_on_earth\/","title":{"rendered":"La vie sur la terre"},"content":{"rendered":"
\n

Personne ne sait comment ni pourquoi la vie est apparue. Nous savons que la vie a commenc\u00e9 sur terre il y a au moins 3,8 milliards (3 800 000 000) d'ann\u00e9es. A cette \u00e9poque, la jeune plan\u00e8te s'\u00e9tait refroidie et recouverte d'une cro\u00fbte rocheuse. Certains scientifiques pensent que la vie a d\u00e9but\u00e9 dans une flaque au milieu des rochers ou dans l'oc\u00e9an. D'autres pensent qu'elle est peut-\u00eatre venue de l'espace avec des com\u00e8tes et des ast\u00e9ro\u00efdes.<\/p>\n<\/div>\n

Dans l'\u00e9tat actuel de nos connaissances, la terre est le seul lieu accueillant la vie. O\u00f9 que se porte le regard sur notre plan\u00e8te, les bact\u00e9ries et d'autres formes simples de vie l'ont colonis\u00e9e.<\/p>\n

Les plantes et les animaux ont besoin de la lumi\u00e8re du soleil pour grandir. Jusque dans les ann\u00e9es 1970, les scientifiques pensaient que la vie n'existait qu'\u00e0 proximit\u00e9 de la surface de la Terre.<\/p>\n

\"Mars
Mars, vue \u00e0 5,5 millions de km, photo prise le 1er d\u00e9cembre<\/figcaption><\/figure>\n

Depuis lors, des bact\u00e9ries ont \u00e9t\u00e9 d\u00e9couvertes \u00e0 plusieurs kilom\u00e8tres de profondeur dans des roches massives. Elles se nourrissent de gaz et des min\u00e9raux de la roche. Des bact\u00e9ries ont aussi \u00e9t\u00e9 d\u00e9couvertes dans des acides forts, dans les froideurs glaciales de l'Antarctique et pr\u00e8s de sources chaudes dans les profondeurs obscures de l'oc\u00e9an. Certaines peuvent m\u00eame survivre dans des sites fortement radioactifs. La vie semble capable de s'implanter partout o\u00f9 de l'eau est disponible.<\/p>\n

Si la vie est si robuste, pourrait-elle d\u00e9marrer et survivre sur d'autres mondes? Le lieu d\u2019accueil le plus propice dans notre syst\u00e8me solaire est la plan\u00e8te Mars.<\/p>","protected":false},"excerpt":{"rendered":"

No one knows how or why life began. We do know that life on Earth started at least 3.8 billion (3 800 000 000) years ago. By this time, the […]<\/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\/07\/life_in_extreme_conditions_on_earth_raises_hopes_for_life_elsewhere_in_the_universe2\/17864454-3-eng-GB\/Life_in_extreme_conditions_on_Earth_raises_hopes_for_life_elsewhere_in_the_universe.jpg","esa_banner_description":"","esa_banner_credit":"ESA","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2001\/07\/Life_in_extreme_conditions_on_Earth_raises_hopes_for_life_elsewhere_in_the_universe2","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":[2],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-1142","post","type-post","status-publish","format-standard","hentry","category-are-we-alone","category-learn","category-life-in-space","tag-background-article"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/1142","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=1142"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/1142\/revisions"}],"predecessor-version":[{"id":4868,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/1142\/revisions\/4868"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=1142"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=1142"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=1142"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=1142"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=1142"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=1142"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=1142"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=1142"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=1142"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=1142"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}