{"id":193,"date":"2021-12-02T12:45:12","date_gmt":"2021-12-02T11:45:12","guid":{"rendered":"https:\/\/kids.esa.int\/comets\/"},"modified":"2026-10-08T00:25:20","modified_gmt":"2026-10-07T22:25:20","slug":"comets","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/comets\/","title":{"rendered":"Com\u00e8tes"},"content":{"rendered":"
\n

Nos anc\u00eatres avaient peur des com\u00e8tes, ils disaient qu'elles portaient malheur ou encore qu'elles annon\u00e7aient des catastrophes. Nous savons aujourd'hui que les com\u00e8tes sont de petites boules de glace qui restent apr\u00e8s la formation des plan\u00e8tes. On pense que des milliards de com\u00e8tes existent \u00e0 la lisi\u00e8re du Syst\u00e8me Solaire, au-del\u00e0 de l'orbite de Pluton.<\/p>\n<\/div>\n

La plupart des com\u00e8tes sont si petites et si \u00e9loign\u00e9es que nous ne pouvons pas les voir, m\u00eame avec les plus grands t\u00e9lescopes. Mais nous pouvons les observer lorsqu\u2019elles se rapprochent du Soleil et d\u00e9veloppent une queue de gaz et de poussi\u00e8re. (Le mot \u2018 com\u00e8te \u2019 signifie \u00ab \u00e9toile chevelue \u00bb.)<\/p>\n

La chaleur du Soleil transforme la glace en gaz qui flotte sur des millions de kilom\u00e8tres dans l'espace. Malgr\u00e9 leur longueur impressionnante, les particules de poussi\u00e8re qu'elles contiennent ne sont pas plus grandes qu'un grain de sable.<\/p>\n

\"Rosetta
Rosetta \u2013 la chasseuse de com\u00e8tes<\/figcaption><\/figure>\n

Certaines com\u00e8tes ne mettent que quelques ann\u00e9es \u00e0 effectuer une orbite autour du Soleil. D\u2019autres, comme la com\u00e8te de Halley, mettent beaucoup plus de temps. D\u2019autres encore n\u2019apparaissent qu\u2019une seule fois et ne sont plus jamais revues. La sonde SOHO de l'ESA a permis de d\u00e9couvrir des milliers de petites com\u00e8tes qui passent tr\u00e8s pr\u00e8s du Soleil. Beaucoup d'entre elles s'\u00e9crasent sur le Soleil ou sont d\u00e9chiquet\u00e9es par sa forte gravit\u00e9.<\/p>\n

En 2014, la sonde spatiale europ\u00e9enne Rosetta entrera dans l'histoire en se pla\u00e7ant en orbite autour d'une com\u00e8te et en y d\u00e9posant un atterrisseur.<\/p>","protected":false},"excerpt":{"rendered":"

Ancient people were afraid of comets \u2013 they were said to bring bad luck or foretell disaster. We now know that comets are small ice worlds that have been left […]<\/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\/giotto_s_art_shows_a_comet_in_the_background2\/17913109-2-eng-GB\/Giotto_s_art_shows_a_comet_in_the_background.jpg","esa_banner_description":"Giotto's art shows a comet in the background","esa_banner_credit":"ESA","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2003\/04\/Giotto_s_art_shows_a_comet_in_the_background2","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-193","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\/193","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=193"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/193\/revisions"}],"predecessor-version":[{"id":4350,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/193\/revisions\/4350"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=193"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=193"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=193"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=193"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=193"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=193"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=193"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=193"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=193"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=193"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}