{"id":923,"date":"2004-11-16T10:04:00","date_gmt":"2004-11-16T09:04:00","guid":{"rendered":"https:\/\/kids.esa.int\/exploring_asteroids\/"},"modified":"2026-10-08T00:33:49","modified_gmt":"2026-10-07T22:33:49","slug":"exploring_asteroids","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/exploring_asteroids\/","title":{"rendered":"\u00c0 la d\u00e9couverte des ast\u00e9ro\u00efdes"},"content":{"rendered":"
\n

La plupart des ast\u00e9ro\u00efdes sont si petits et si \u00e9loign\u00e9s que nous ne pouvons les distinguer que sous la forme de minuscules points lumineux. On les rep\u00e8re gr\u00e2ce \u00e0 leur passage devant les \u2018 \u00e9toiles fixes \u2019 du ciel nocturne. Nous en apprenons davantage \u00e0 leur sujet en utilisant de grands t\u00e9lescopes pour \u00e9tudier la lumi\u00e8re qu\u2019ils r\u00e9fl\u00e9chissent.<\/p>\n<\/div>\n

Cependant, m\u00eame le t\u00e9lescope spatial Hubble ne parvient pas \u00e0 nous en apprendre beaucoup \u00e0 leur sujet. L\u2019un des ast\u00e9ro\u00efdes les plus int\u00e9ressants est Vesta, riche en m\u00e9taux. Les images de Hubble montrent un corps c\u00e9leste assez rond, dot\u00e9 d\u2019un grand crat\u00e8re d\u2019impact.<\/p>\n

Certains ast\u00e9ro\u00efdes fr\u00f4lant la Terre ont \u00e9t\u00e9 \u00e9tudi\u00e9s \u00e0 l'aide d'un radar. Les \u00e9chos radar sont capt\u00e9s par de grands radiot\u00e9lescopes et permettent de d\u00e9terminer leur forme et leur taille.<\/p>\n

Quelques ast\u00e9ro\u00efdes ont fait l'objet d'\u00e9tudes plus approfondies gr\u00e2ce \u00e0 des sondes spatiales qui se sont rendues sur place. Les images montrent des objets parsem\u00e9s de nombreux crat\u00e8res, ce qui t\u00e9moigne des collisions dont ils ont \u00e9t\u00e9 victimes au cours de milliards d'ann\u00e9es. En 2000, NEAR Shoemaker est devenu le premier vaisseau spatial \u00e0 se mettre en orbite autour d\u2019un ast\u00e9ro\u00efde. Il a termin\u00e9 sa mission par un atterrissage historique sur \u00c9ros, l\u2019un des plus grands ast\u00e9ro\u00efdes proches de la Terre.<\/p>\n

La sonde Rosetta de l\u2019ESA a \u00e9galement survol\u00e9 deux ast\u00e9ro\u00efdes de la ceinture principale \u2013 Steins et Lutetia \u2013 lors de son voyage vers une com\u00e8te. Avec un diam\u00e8tre d\u2019environ 130 km, Lutetia \u00e9tait le plus grand ast\u00e9ro\u00efde jamais visit\u00e9 par un engin spatial. L\u2019ESA \u00e9tudie \u00e9galement des moyens de d\u00e9vier de sa trajectoire un ast\u00e9ro\u00efde se dirigeant vers la Terre.<\/p>","protected":false},"excerpt":{"rendered":"

Most asteroids are so small and so far away that we can only see them as tiny points of light. They are found through their movement in front of 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\/2003\/04\/asteroids_come_in_many_shapes_and_sizes2\/17886580-2-eng-GB\/Asteroids_come_in_many_shapes_and_sizes.jpg","esa_banner_description":"Asteroids come in many shapes and sizes","esa_banner_credit":"courtesy Observatoire de Paris","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2003\/04\/Asteroids_come_in_many_shapes_and_sizes2","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":[46,10,11],"tags":[2],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-923","post","type-post","status-publish","format-standard","hentry","category-comets-and-meteors","category-learn","category-our-universe","tag-background-article"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/923","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=923"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/923\/revisions"}],"predecessor-version":[{"id":2066,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/923\/revisions\/2066"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=923"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=923"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=923"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=923"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=923"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=923"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=923"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=923"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=923"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=923"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}