{"id":26334,"date":"2024-10-24T12:00:31","date_gmt":"2024-10-24T10:00:31","guid":{"rendered":"https:\/\/www.laterredufutur.com\/accueil\/?p=26334"},"modified":"2024-10-23T13:10:20","modified_gmt":"2024-10-23T11:10:20","slug":"le-jwst-telescope-james-webb-repere-le-premier-monde-de-vapeur-deau-connu","status":"publish","type":"post","link":"https:\/\/www.laterredufutur.com\/accueil\/le-jwst-telescope-james-webb-repere-le-premier-monde-de-vapeur-deau-connu\/","title":{"rendered":"Le JWST (telescope James Webb) rep\u00e8re le premier \u00ab monde de vapeur d&rsquo;eau\u00bb connu"},"content":{"rendered":"<div class=\"1665f18d14f35dd9e7566e1a8ac9a3e9\" data-index=\"1\" style=\"float: none; margin:10px 0 10px 0; text-align:center;\">\n<script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block; text-align:center;\"\r\n     data-ad-layout=\"in-article\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-client=\"ca-pub-2860849627502538\"\r\n     data-ad-slot=\"3019501113\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script>\n<\/div>\n<p>Au-del\u00e0 de notre syst\u00e8me solaire, la pression de ce monde aquatique pourrait cr\u00e9er des formes de mati\u00e8re bizarres. L&rsquo;atmosph\u00e8re de cette exoplan\u00e8te fonctionne \u00e0 plein r\u00e9gime.<\/p>\n<p>Une plan\u00e8te situ\u00e9e au-del\u00e0 de notre syst\u00e8me solaire, appel\u00e9e GJ 9827d, poss\u00e8de une atmosph\u00e8re presque enti\u00e8rement compos\u00e9e de mol\u00e9cules d&rsquo;eau chaude, rapportent des astronomes dans les Astrophysical Journal Letters du 4 octobre.<\/p>\n<p>Nous utilisons le terme de \u00ab monde \u00e0 vapeur \u00bb \u00bb, explique l&rsquo;astronome Ryan MacDonald de l&rsquo;universit\u00e9 du Michigan \u00e0 Ann Arbor.<\/p>\n<p>GJ 9827d a \u00e9t\u00e9 d\u00e9couverte en 2017 en orbite autour d&rsquo;une \u00e9toile situ\u00e9e \u00e0 environ 100 ann\u00e9es-lumi\u00e8re de la Terre. Avec une taille deux fois sup\u00e9rieure \u00e0 celle de la Terre et une masse trois fois sup\u00e9rieure \u00e0 celle de la Terre, il s&rsquo;agit d&rsquo;un type de plan\u00e8te appel\u00e9 sous-Neptune (SN : 8\/8\/22). Les mondes de ce type sont les plus courants dans la galaxie, bien que notre syst\u00e8me solaire n&rsquo;en poss\u00e8de aucun.<\/p>\n<p>Mais il ne suffit pas de conna\u00eetre la taille et la masse de la plan\u00e8te pour en d\u00e9duire sa composition. Pour sonder le ciel des exoplan\u00e8tes, les astronomes analysent la lumi\u00e8re des \u00e9toiles filtrant \u00e0 travers l&rsquo;atmosph\u00e8re de la plan\u00e8te lorsqu&rsquo;elle passe devant son \u00e9toile m\u00e8re (SN : 6\/7\/24).<\/p>\n<p>MacDonald et ses coll\u00e8gues ont utilis\u00e9 le t\u00e9lescope spatial James Webb pour observer deux passages, ou transits, de GJ 9827d en novembre 2023. Le t\u00e9lescope spatial Hubble avait fait des observations similaires et avait vu des signes de mol\u00e9cules d&rsquo;eau dans l&rsquo;atmosph\u00e8re de la plan\u00e8te, ont rapport\u00e9 les astronomes l&rsquo;ann\u00e9e derni\u00e8re. Mais cela ne suffisait pas \u00e0 d\u00e9terminer si l&rsquo;atmosph\u00e8re contenait simplement un peu d&rsquo;eau ou s&rsquo;il s&rsquo;agissait d&rsquo;un monde aquatique \u00e0 part enti\u00e8re.<\/p><div class=\"1665f18d14f35dd9e7566e1a8ac9a3e9\" data-index=\"2\" style=\"float: none; margin:10px 0 10px 0; text-align:center;\">\n<script async src=\"https:\/\/pagead2.googlesyndication.com\/pagead\/js\/adsbygoogle.js\"><\/script>\r\n<ins class=\"adsbygoogle\"\r\n     style=\"display:block; text-align:center;\"\r\n     data-ad-layout=\"in-article\"\r\n     data-ad-format=\"fluid\"\r\n     data-ad-client=\"ca-pub-2860849627502538\"\r\n     data-ad-slot=\"3019501113\"><\/ins>\r\n<script>\r\n     (adsbygoogle = window.adsbygoogle || []).push({});\r\n<\/script>\n<\/div>\n\n<p>En combinant les images des deux t\u00e9lescopes, il est apparu clairement que l&rsquo;atmosph\u00e8re \u00e9tait presque enti\u00e8rement constitu\u00e9e d&rsquo;eau. La temp\u00e9rature de la plan\u00e8te \u00e9tant d&rsquo;environ 340\u00b0 Celsius, toute cette eau devrait \u00eatre sous forme de vapeur.<\/p>\n<p>De tels mondes de vapeur \u00ab ont \u00e9t\u00e9 pr\u00e9dits, mais il s&rsquo;agit de la premi\u00e8re preuve observationnelle qu&rsquo;ils existent r\u00e9ellement \u00bb, explique M. Macdonald. \u00ab J&rsquo;ai l&rsquo;impression d&rsquo;\u00eatre un explorateur de Star Trek.<\/p>\n<p>Il est possible qu&rsquo;il n&rsquo;y ait pas de surface rocheuse solide sous le ciel vaporeux de la plan\u00e8te. Dans les profondeurs de l&rsquo;atmosph\u00e8re, la pression de toute cette eau devrait \u00eatre suffisamment \u00e9lev\u00e9e pour forcer les mol\u00e9cules d&rsquo;eau \u00e0 se transformer en formes de mati\u00e8re \u00e9tranges et exotiques, comme des fluides supercritiques ou des glaces chaudes \u00e0 haute pression, explique M. MacDonald.<\/p>\n<p>Cela fait de GJ 9827d un endroit peu propice \u00e0 la d\u00e9couverte de la vie. Mais l&rsquo;\u00e9tude de son atmosph\u00e8re est une bonne pratique pour l&rsquo;observation de plan\u00e8tes qui pourraient \u00eatre habitables.<\/p>\n<p>\u00ab C&rsquo;est la preuve de principe que nous pouvons d\u00e9tecter des atmosph\u00e8res plus lourdes \u00bb, explique M. MacDonald. \u00ab Nous sommes sur la bonne voie pour atteindre nos objectifs en mati\u00e8re d&rsquo;astrobiologie.<\/p>\n<p>Adaptation <a href=\"https:\/\/www.laterredufutur.com\/accueil\/\" rel=\"noopener\" target=\"_blank\">Terra Projects<\/a><\/p>\n<p>Source : <a href=\"https:\/\/www.sciencenews.org\/article\/jwst-spots-the-first-known-steam-world\" rel=\"noopener\" target=\"_blank\">https:\/\/www.sciencenews.org\/<\/a><\/p>\n<p class=\"bawpvc-ajax-counter\" data-id=\"26334\">(152)<\/p>\n<!--CusAds0-->\n<div style=\"font-size: 0px; height: 0px; line-height: 0px; margin: 0; padding: 0; clear: both;\"><\/div>","protected":false},"excerpt":{"rendered":"<p>Au-del\u00e0 de notre syst\u00e8me solaire, la pression de ce monde aquatique pourrait cr\u00e9er des formes de mati\u00e8re bizarres. L&rsquo;atmosph\u00e8re de&#8230;<\/p>\n","protected":false},"author":1,"featured_media":26335,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"ngg_post_thumbnail":0,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[22],"tags":[252,359,1947,8166],"class_list":["post-26334","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-espace","tag-atmosphere","tag-exoplanete","tag-james-webb","tag-vapeau","wpcat-22-id"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2024\/10\/exoplanete.webp?fit=1030%2C580&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p631RN-6QK","jetpack-related-posts":[{"id":27390,"url":"https:\/\/www.laterredufutur.com\/accueil\/a-18-annees-lumiere-de-notre-systeme-solaire-une-super-terre-pourrait-abriter-la-vie\/","url_meta":{"origin":26334,"position":0},"title":"A 18 ann\u00e9es-lumi\u00e8re de notre Syst\u00e8me solaire, une super-Terre pourrait abriter la vie","author":"Admin","date":"27 octobre 2025","format":false,"excerpt":"La chasse aux mondes habitables franchit un nouveau cap avec la d\u00e9couverte de GJ 251c, une exoplan\u00e8te situ\u00e9e \u00e0 seulement 18 ann\u00e9es-lumi\u00e8re. Voici pourquoi ce monde suscite tant d\u2019espoirs dans la recherche de vie extraterrestre. GJ 251c : une exoplan\u00e8te massive, temp\u00e9r\u00e9e et potentiellement habitable Les astronomes ont identifi\u00e9 GJ\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2020\/10\/exoplanete.jpg?fit=1200%2C575&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2020\/10\/exoplanete.jpg?fit=1200%2C575&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2020\/10\/exoplanete.jpg?fit=1200%2C575&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2020\/10\/exoplanete.jpg?fit=1200%2C575&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2020\/10\/exoplanete.jpg?fit=1200%2C575&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":25249,"url":"https:\/\/www.laterredufutur.com\/accueil\/le-telescope-james-webb-decouvre-du-methane-et-du-dioxyde-de-carbone-dans-latmosphere-de-k2-18-b\/","url_meta":{"origin":26334,"position":1},"title":"Le t\u00e9lescope James Webb d\u00e9couvre du m\u00e9thane et du dioxyde de carbone dans l&rsquo;atmosph\u00e8re de K2-18 b","author":"Admin","date":"27 septembre 2023","format":false,"excerpt":"Une nouvelle observation de K2-18 b, une exoplan\u00e8te 8,6 fois plus massive que la Terre, par le t\u00e9lescope spatial James Webb de la NASA a r\u00e9v\u00e9l\u00e9 la pr\u00e9sence de mol\u00e9cules contenant du carbone, notamment du m\u00e9thane et du dioxyde de carbone. La d\u00e9couverte de M. Webb vient s'ajouter \u00e0 de\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2023\/09\/exoplanete-K2-18b.jpg?fit=985%2C554&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2023\/09\/exoplanete-K2-18b.jpg?fit=985%2C554&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2023\/09\/exoplanete-K2-18b.jpg?fit=985%2C554&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2023\/09\/exoplanete-K2-18b.jpg?fit=985%2C554&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":14996,"url":"https:\/\/www.laterredufutur.com\/accueil\/des-scientifiques-viennent-de-detecter-une-atmosphere-sur-une-exoplanete\/","url_meta":{"origin":26334,"position":2},"title":"Des scientifiques viennent de d\u00e9tecter une atmosph\u00e8re sur une exoplan\u00e8te","author":"Admin","date":"15 avril 2017","format":false,"excerpt":"La recherche de formes de vie extraterrestre est sans doute l\u2019une des qu\u00eates les plus exaltantes de l\u2019univers. Des chercheurs viennent de d\u00e9couvrir une atmosph\u00e8re autour de Gliese 1132b, une exoplan\u00e8te de la taille de la Terre, faisant d\u2019elle une candidate potentielle au d\u00e9veloppement de la vie. LA D\u00c9COUVERTE D\u2019UNE\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/04\/GJ-1132b.jpg?fit=904%2C508&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/04\/GJ-1132b.jpg?fit=904%2C508&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/04\/GJ-1132b.jpg?fit=904%2C508&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2017\/04\/GJ-1132b.jpg?fit=904%2C508&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":25610,"url":"https:\/\/www.laterredufutur.com\/accueil\/une-planete-contenant-de-leau-dans-son-atmosphere-decouverte-par-hubble\/","url_meta":{"origin":26334,"position":3},"title":"Une plan\u00e8te contenant de l&rsquo;eau dans son atmosph\u00e8re d\u00e9couverte par Hubble","author":"Admin","date":"21 f\u00e9vrier 2024","format":false,"excerpt":"Op\u00e9rant comme un radar spatial, le t\u00e9lescope Hubble aurait d\u00e9couvert l\u2019existence d\u2019une plan\u00e8te contenant de l\u2019eau dans son atmosph\u00e8re. Cette plan\u00e8te r\u00e9pond au nom de GJ 9827 et fait deux fois le diam\u00e8tre de la Terre. Situ\u00e9e \u00e0 96 ann\u00e9es-lumi\u00e8re de la Terre, dans la constellation des Poissons, l\u2019\u00e9toile GJ\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2024\/02\/exoplanete.jpg?fit=1024%2C1024&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2024\/02\/exoplanete.jpg?fit=1024%2C1024&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2024\/02\/exoplanete.jpg?fit=1024%2C1024&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2024\/02\/exoplanete.jpg?fit=1024%2C1024&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":24289,"url":"https:\/\/www.laterredufutur.com\/accueil\/le-telescope-james-webb-vient-de-prouver-quil-peut-detecter-des-signes-de-vie-dans-les-atmospheres-des-planetes-et-exoplanetes\/","url_meta":{"origin":26334,"position":4},"title":"Le t\u00e9lescope James Webb vient de prouver qu&rsquo;il peut d\u00e9tecter des signes de vie dans les atmosph\u00e8res des plan\u00e8tes et exoplan\u00e8tes","author":"Admin","date":"11 ao\u00fbt 2022","format":false,"excerpt":"Les ingr\u00e9dients de la vie sont r\u00e9partis dans l'Univers. Si la Terre est le seul endroit connu de l'Univers o\u00f9 la vie est pr\u00e9sente, la d\u00e9tection de la vie au-del\u00e0 de la Terre est un objectif majeur de l'astronomie moderne et de la science plan\u00e9taire. Nous sommes deux scientifiques \u00e0\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2022\/08\/exoplanete-trappist.jpg?fit=1024%2C415&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2022\/08\/exoplanete-trappist.jpg?fit=1024%2C415&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2022\/08\/exoplanete-trappist.jpg?fit=1024%2C415&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2022\/08\/exoplanete-trappist.jpg?fit=1024%2C415&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":27642,"url":"https:\/\/www.laterredufutur.com\/accueil\/la-nasa-lance-le-telescope-pandora-faisant-passer-la-recherche-de-mondes-habitables-par-le-jwst-a-un-niveau-superieur\/","url_meta":{"origin":26334,"position":5},"title":"La NASA lance le t\u00e9lescope Pandora, faisant passer la recherche de mondes habitables par le JWST \u00e0 un niveau sup\u00e9rieur","author":"Admin","date":"22 janvier 2026","format":false,"excerpt":"La recherche d'exoplan\u00e8tes habitables men\u00e9e par le t\u00e9lescope James Webb b\u00e9n\u00e9ficie d'un coup de pouce important gr\u00e2ce \u00e0 son nouveau compagnon d'observation des \u00e9toiles, Pandora. Le 11 janvier 2026, j'ai regard\u00e9 avec anxi\u00e9t\u00e9, depuis la base spatiale de Vandenberg en Californie, un lieu \u00e9troitement contr\u00f4l\u00e9, une fus\u00e9e Falcon 9 de\u2026","rel":"","context":"Dans &quot;Espace&quot;","block_context":{"text":"Espace","link":"https:\/\/www.laterredufutur.com\/accueil\/sujets\/espace\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2024\/02\/exoplanete.jpg?fit=1024%2C1024&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2024\/02\/exoplanete.jpg?fit=1024%2C1024&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2024\/02\/exoplanete.jpg?fit=1024%2C1024&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/www.laterredufutur.com\/accueil\/wp-content\/uploads\/2024\/02\/exoplanete.jpg?fit=1024%2C1024&ssl=1&resize=700%2C400 2x"},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/26334","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/comments?post=26334"}],"version-history":[{"count":1,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/26334\/revisions"}],"predecessor-version":[{"id":26336,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/posts\/26334\/revisions\/26336"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media\/26335"}],"wp:attachment":[{"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/media?parent=26334"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/categories?post=26334"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laterredufutur.com\/accueil\/wp-json\/wp\/v2\/tags?post=26334"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}