{"id":623,"date":"2013-10-02T11:25:00","date_gmt":"2013-10-02T09:25:00","guid":{"rendered":"https:\/\/kids.esa.int\/europe_prepares_to_map_a_billion_stars\/"},"modified":"2026-10-08T00:30:23","modified_gmt":"2026-10-07T22:30:23","slug":"europe_prepares_to_map_a_billion_stars","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/europe_prepares_to_map_a_billion_stars\/","title":{"rendered":"L\u2019Europe se pr\u00e9pare \u00e0 cartographier un milliard d\u2019\u00e9toiles"},"content":{"rendered":"<div class=\"lede\">\n<p>Le plus puissant satellite astrom\u00e9trique jamais con\u00e7u sera lanc\u00e9 le 19 d\u00e9cembre prochain depuis le port spatial de l\u2019Europe, en Guyane fran\u00e7aise. Une fus\u00e9e Soyouz va envoyer cet observatoire spatial de 2 tonnes, baptis\u00e9 Gaia, jusqu\u2019\u00e0 1,5 million de kilom\u00e8tres de la Terre. Une fois dans l\u2019espace, Gaia va passer les cinq prochaines ann\u00e9es \u00e0 \u00e9tudier environ un milliard d\u2019\u00e9toiles de la Voie lact\u00e9e.<\/p>\n<\/div>\n<p>Gaia devrait nous transmettre les donn\u00e9es les plus pr\u00e9cises jamais obtenues sur la position, le mouvement et la luminosit\u00e9 de ces \u00e9toiles. Chacune de ces \u00e9toiles sera observ\u00e9e environ 70 fois pendant cette mission de cinq ans. Gaia va effectuer une moyenne de 40 millions d\u2019observations par jour ! La position des corps c\u00e9lestes (dont la luminosit\u00e9 sera parfois 4 000 fois plus faible que la limite d\u00e9celable \u00e0 l\u2019\u0153il nu) sera mesur\u00e9e avec une pr\u00e9cision incroyable, qui reviendrait \u00e0 mesurer le diam\u00e8tre d\u2019un cheveu humain \u00e0 une distance de 1 000 kilom\u00e8tres !<\/p>\n<p>Pour atteindre cette pr\u00e9cision remarquable, Gaia est \u00e9quip\u00e9 d\u2019un \u201c \u0153il \u201d ultrasensible, la plus grande cam\u00e9ra num\u00e9rique jamais envoy\u00e9e dans l\u2019espace. Cela permettra \u00e0 Gaia de d\u00e9tecter des objets un million de fois plus faibles que ce que nos yeux peuvent percevoir. Il embarque \u00e9galement deux t\u00e9lescopes optiques et trois instruments scientifiques, ainsi qu\u2019une \u201c jupe \u201d de 10 m\u00e8tres de large qui sert de pare-soleil et produit de l\u2019\u00e9nergie solaire.<\/p>\n<figure class=\"wp-block-image size-large\" data-width=\"1500\" data-credit=\"ESA\/Herschel\/PACS\/SPIRE\/J.Fritz, U.Gent\/XMM-Newton\/EPIC\/W. Pietsch, MPE\" data-detail-url=\"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2011\/12\/Andromeda_Galaxy_in_infrared_and_X-rays2\" data-licence=\"ESA Standard Licence\" data-licence-url=\"https:\/\/www.esa.int\/ESA_Multimedia\/Terms_and_conditions_of_use_of_images_and_videos_available_on_the_esa_website\"><img decoding=\"async\" loading=\"lazy\" style=\"max-width:100%;height:auto\" src=\"https:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2011\/12\/andromeda_galaxy_in_infrared_and_x-rays2\/17896053-2-eng-GB\/Andromeda_Galaxy_in_infrared_and_X-rays.jpg\" alt=\"Andromeda Galaxy in infrared and X-rays\"><figcaption>La galaxie d'Androm\u00e8de en infrarouge et en rayons X<\/figcaption><\/figure>\n<p>La principale t\u00e2che de Gaia consistera \u00e0 cartographier notre galaxie en 3D. Cette ambitieuse mission devrait \u00e9galement permettre de d\u00e9couvrir des centaines d\u2019ast\u00e9ro\u00efdes et de com\u00e8tes du syst\u00e8me solaire, des naines brunes (des \u00ab \u00e9toiles avort\u00e9es \u00bb en raison de leur masse trop faible), environ 20 000 supernovas (des ph\u00e9nom\u00e8nes lumineux se produisant lors de l\u2019explosion d\u2019une \u00e9toile) et des centaines de milliers de quasars (des galaxies actives).<\/p>\n<p>Gaia devrait aussi faire la d\u00e9couverte d\u2019au moins 7 000 plan\u00e8tes en orbite autour d\u2019\u00e9toiles distantes, en d\u00e9tectant les variations de la position d\u2019une \u00e9toile caus\u00e9es par la force gravitationnelle d\u2019une plan\u00e8te \u00e0 proximit\u00e9. D\u2019ici la fin de sa mission, Gaia nous aura transmis environ un p\u00e9taoctet de donn\u00e9es (soit un million de gigaoctets, de quoi remplir 200 000 DVD !).<\/p>","protected":false},"excerpt":{"rendered":"<p>The most powerful star mapper ever built will be launched from Europe\u2019s spaceport in French Guiana on 19 December. A Soyuz rocket will send the 2 tonne space observatory, known [&hellip;]<\/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\/2013\/10\/artist_s_impression_of_gaia\/17906940-2-eng-GB\/Artist_s_impression_of_Gaia.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\/2013\/10\/Artist_s_impression_of_Gaia","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":[26],"tags":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-623","post","type-post","status-publish","format-standard","hentry","category-news"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/623","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=623"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/623\/revisions"}],"predecessor-version":[{"id":4590,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/623\/revisions\/4590"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=623"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=623"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=623"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=623"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=623"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=623"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=623"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=623"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=623"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=623"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}