{"id":823,"date":"2004-12-09T15:52:00","date_gmt":"2004-12-09T14:52:00","guid":{"rendered":"https:\/\/kids.esa.int\/space_velocity\/"},"modified":"2026-10-08T00:32:41","modified_gmt":"2026-10-07T22:32:41","slug":"space_velocity","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/ro\/space_velocity\/","title":{"rendered":"Viteza spa\u021bial\u0103"},"content":{"rendered":"
\n

Obiectele care se deplaseaz\u0103 \u00een jurul unei planete se numesc sateli\u021bi. Fiecare parcurs complet pe care \u00eel face un satelit \u00een jurul planetei se nume\u0219te orbit\u0103.<\/p>\n<\/div>\n

P\u0103m\u00e2ntul nostru are un singur satelit natural \u2013 Luna. Cu toate acestea, \u00eencep\u00e2nd din octombrie 1957, mii de sateli\u021bi artificiali (crea\u021bi de om) au fost plasa\u021bi pe orbite \u00een jurul P\u0103m\u00e2ntului.<\/p>\n

Pentru a r\u0103m\u00e2ne pe orbit\u0103, un satelit trebuie s\u0103 se deplaseze cu o vitez\u0103 foarte mare, care depinde de altitudine. Astfel, de regul\u0103, pentru o orbit\u0103 circular\u0103 la o altitudine de 300 km deasupra suprafe\u021bei P\u0103m\u00e2ntului, este necesar\u0103 o vitez\u0103 de 7,8 km\/s (28.000 km\/h). La aceast\u0103 vitez\u0103, satelitul va parcurge o orbit\u0103 complet\u0103 \u00een jurul P\u0103m\u00e2ntului \u00een 90 de minute.<\/p>\n

Sateli\u021bii trebuie s\u0103 se mi\u0219te at\u00e2t de repede pentru a compensa atrac\u021bia gravita\u021bional\u0103 a P\u0103m\u00e2ntului. Este similar cu situa\u021bia \u00een care cineva arunc\u0103 o minge de cricket sau de baseball. Cu c\u00e2t mingea este aruncat\u0103 mai tare, cu at\u00e2t va parcurge o distan\u021b\u0103 mai mare \u00eenainte de a ajunge la sol.<\/p>\n

Dac\u0103 un juc\u0103tor ar putea arunca mingea cu suficient\u0103 for\u021b\u0103 \u00eenc\u00e2t aceasta s\u0103 ating\u0103 viteza necesar\u0103, mingea ar intra pe orbit\u0103. Nu s-ar mai \u00eentoarce niciodat\u0103 pe P\u0103m\u00e2nt. Arunc-o \u0219i mai tare, astfel \u00eenc\u00e2t s\u0103 ating\u0103 o vitez\u0103 de 11,2 km\/s (40.300 km\/h) \u2013 cunoscut\u0103 sub numele de \u2018viteza de evadare\u2019 \u2013 \u0219i mingea va p\u0103r\u0103si definitiv P\u0103m\u00e2ntul. Va deveni atunci un \u2018satelit\u2019 al Soarelui.<\/p>","protected":false},"excerpt":{"rendered":"

Objects that travel around a planet are called satellites. Each complete journey a satellite makes around the planet is called an orbit. Our Earth has one natural satellite \u2013 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\/2004\/12\/newton_s_cannon2\/17886950-2-eng-GB\/Newton_s_cannon.gif","esa_banner_description":"","esa_banner_credit":"ESA","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2004\/12\/Newton_s_cannon2","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":[10,65,40],"tags":[2],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-823","post","type-post","status-publish","format-standard","hentry","category-learn","category-mission-control","category-technology","tag-background-article"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/posts\/823","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/comments?post=823"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/posts\/823\/revisions"}],"predecessor-version":[{"id":1966,"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/posts\/823\/revisions\/1966"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/media?parent=823"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/categories?post=823"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/tags?post=823"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/panel?post=823"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/language?post=823"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/age?post=823"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/duration?post=823"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/resource_type?post=823"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/audience?post=823"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/ro\/wp-json\/wp\/v2\/wf_post_folders?post=823"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}