{"id":604,"date":"2013-12-19T09:40:00","date_gmt":"2013-12-19T08:40:00","guid":{"rendered":"https:\/\/kids.esa.int\/liftoff_for_gaia\/"},"modified":"2026-10-08T00:30:10","modified_gmt":"2026-10-07T22:30:10","slug":"liftoff_for_gaia","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/liftoff_for_gaia\/","title":{"rendered":"D\u00e9collage de Gaia"},"content":{"rendered":"
\n

Ce matin, le satellite Gaia de l\u2019ESA a \u00e9t\u00e9 lanc\u00e9 par une fus\u00e9e Soyouz depuis le port spatial de l\u2019Europe \u00e0 Kourou, en Guyane fran\u00e7aise. Il va entamer une incroyable mission portant sur l\u2019\u00e9tude d\u2019un milliard d\u2019\u00e9toiles.<\/p>\n<\/div>\n

Gaia va \u00e9laborer la cartographie la plus pr\u00e9cise et la plus d\u00e9taill\u00e9e jamais r\u00e9alis\u00e9e de la Voie lact\u00e9e. En r\u00e9alisant des mesures pr\u00e9cises de la position et du mouvement d\u2019un milliard d\u2019\u00e9toiles, il r\u00e9pondra \u00e0 une partie de nos questions sur l\u2019origine et l\u2019\u00e9volution de notre Galaxie.<\/p>\n

Gaia fait d\u00e9sormais route vers une orbite d\u00e9finie pr\u00e8s d\u2019un point virtuel d\u00e9nomm\u00e9 L2, \u00e0 1,5 million de kilom\u00e8tres de la Terre dans la direction anti-solaire.<\/p>\n

\"Gaia\"
Gaia<\/figcaption><\/figure>\n

En balayant le ciel de fa\u00e7on continue, Gaia observera chaque \u00e9toile en moyenne 70 fois en cinq ans. L\u2019observatoire spatial mesurera la position et les principales caract\u00e9ristiques physiques de chaque \u00e9toile, y compris leur brillance, leur temp\u00e9rature et leur composition chimique.<\/p>\n

En reconstituant l\u2019historique du d\u00e9placement des \u00e9toiles, nous pourrons apprendre d\u2019o\u00f9 elles viennent et comment la Voie lact\u00e9e s\u2019est constitu\u00e9e sur plusieurs milliards d\u2019ann\u00e9es \u00e0 partir de la fusion de petites galaxies. \u00c0 l\u2019inverse, nous pourrons \u00e9galement anticiper le mouvement des \u00e9toiles et nous projeter dans l\u2019avenir afin d\u2019en savoir plus sur la destin\u00e9e finale de notre galaxie.<\/p>\n

En comparant ses multiples balayages du ciel, Gaia d\u00e9voilera aussi des dizaines de milliers de supernovas, un ph\u00e9nom\u00e8ne se produisant lors de l\u2019explosion des \u00e9toiles en fin de vie. De l\u00e9g\u00e8res oscillations p\u00e9riodiques de la position de certaines \u00e9toiles devraient \u00e9galement r\u00e9v\u00e9ler la pr\u00e9sence de plan\u00e8tes en orbite autour d\u2019elles, responsables de ces perturbations gravitationnelles.<\/p>\n

Gaia l\u00e8vera \u00e9galement le voile sur de nouveaux ast\u00e9ro\u00efdes de notre Syst\u00e8me solaire, tout en affinant l\u2019orbite de ceux que nous connaissons d\u00e9j\u00e0. Ainsi, nous pourrons tester plus pr\u00e9cis\u00e9ment la fameuse th\u00e9orie de la relativit\u00e9 d\u2019Einstein.<\/p>","protected":false},"excerpt":{"rendered":"

ESA\u2019s Gaia mission blasted off this morning on a Soyuz rocket from Europe\u2019s Spaceport in Kourou, French Guiana, on its exciting mission to study a billion suns. Gaia will create […]<\/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\/12\/gaia3_h\/17875111-2-eng-GB\/Gaia3_H.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\/12\/Gaia3_H","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":[10,11,21],"tags":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-604","post","type-post","status-publish","format-standard","hentry","category-learn","category-our-universe","category-stars-and-galaxies"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/604","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=604"}],"version-history":[{"count":5,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/604\/revisions"}],"predecessor-version":[{"id":4575,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/604\/revisions\/4575"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=604"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=604"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=604"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=604"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=604"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=604"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=604"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=604"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=604"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=604"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}