{"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\/fi\/space_velocity\/","title":{"rendered":"Avaruusnopeus"},"content":{"rendered":"
\n

Kappaleita, jotka kiert\u00e4v\u00e4t planeetan ymp\u00e4ri, kutsutaan satelliiteiksi. Satelliitin jokainen t\u00e4ydellinen kierros planeetan ymp\u00e4ri on kiertorata.<\/p>\n<\/div>\n

Maapallollamme on yksi luonnollinen satelliitti \u2013 Kuu. Lokakuusta 1957 l\u00e4htien Maan kiertoradalle on kuitenkin sijoitettu useita tuhansia keinotekoisia (ihmisen rakentamia) satelliitteja.<\/p>\n

Pysy\u00e4kseen kiertoradalla satelliitin on liikkuttava eritt\u00e4in suurella nopeudella, joka riippuu korkeudesta. Tyypillisesti 300 km:n korkeudella maanpinnasta sijaitsevalla py\u00f6re\u00e4ll\u00e4 kiertoradalla tarvitaan siis nopeutta 7,8 km\/s (28 000 km\/h). T\u00e4ll\u00e4 nopeudella satelliitti kiert\u00e4\u00e4 maapallon kerran 90 minuutissa.<\/p>\n

Satelliittien on liikuttava niin nopeasti, jotta ne voivat kompensoida maapallon painovoiman vaikutusta. T\u00e4m\u00e4 on samanlaista kuin kun joku heitt\u00e4\u00e4 krikettipalloa tai baseball-palloa. Mit\u00e4 kovemmin pallo heitet\u00e4\u00e4n, sit\u00e4 pidemm\u00e4lle se lent\u00e4\u00e4 ennen kuin se putoaa maahan.<\/p>\n

Jos pelaaja pystyisi heitt\u00e4m\u00e4\u00e4n pallon niin kovaa, ett\u00e4 se saavuttaisi tarvittavan nopeuden, pallo menisi kiertoradalle. Se ei koskaan putoaisi takaisin Maahan. Heit\u00e4 sit\u00e4 viel\u00e4 kovemmin, niin ett\u00e4 se saavuttaa nopeuden 11,2 km\/s (40 300 km\/h) \u2013 jota kutsutaan \u2018pakonopeudeksi\u2019 \u2013 ja pallo poistuu kokonaan Maasta. Siit\u00e4 tulee sitten Auringon \u2018satelliitti\u2019.<\/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\/fi\/wp-json\/wp\/v2\/posts\/823","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/comments?post=823"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/823\/revisions"}],"predecessor-version":[{"id":1966,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/823\/revisions\/1966"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/media?parent=823"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/categories?post=823"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/tags?post=823"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/panel?post=823"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/language?post=823"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/age?post=823"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/duration?post=823"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/resource_type?post=823"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/audience?post=823"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/wf_post_folders?post=823"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}