{"id":624,"date":"2013-09-19T09:25:00","date_gmt":"2013-09-19T07:25:00","guid":{"rendered":"https:\/\/kids.esa.int\/re-entry_nears_for_esa_s_ferrari_of_space\/"},"modified":"2026-10-08T00:30:24","modified_gmt":"2026-10-07T22:30:24","slug":"re-entry_nears_for_esa_s_ferrari_of_space","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fi\/re-entry_nears_for_esa_s_ferrari_of_space\/","title":{"rendered":"ESAn \u2018avaruuden Ferrarin\u2019 paluu maapallolle l\u00e4hestyy\u2019"},"content":{"rendered":"<div class=\"lede\">\n<p>Yli nelj\u00e4n vuoden kiertoradalla olon j\u00e4lkeen ESA:n GOCE-missio on l\u00e4hestym\u00e4ss\u00e4 loppuaan. Lokakuun puoliv\u00e4liss\u00e4 satelliitin polttoaine loppuu, ja sen kiertorata alkaa heikenty\u00e4. Sen odotetaan palaavan ilmakeh\u00e4\u00e4n noin kolme viikkoa my\u00f6hemmin.<\/p>\n<\/div>\n<p>GOCE on kiert\u00e4nyt Maata maaliskuusta 2009 l\u00e4htien alle 270 km:n korkeudella, mik\u00e4 on tieteelliselle satelliitille poikkeuksellisen matala. Sen teht\u00e4v\u00e4n\u00e4 on ollut kartoittaa Maan pinnan painovoiman pienimpi\u00e4kin vaihteluita ennenn\u00e4kem\u00e4tt\u00f6m\u00e4ll\u00e4 tarkkuudella.<\/p>\n<p>Painovoima on voima, joka vet\u00e4\u00e4 kaiken kohti maata. Maapallon painovoima vaihtelee kuitenkin hieman paikasta toiseen. T\u00e4m\u00e4 johtuu osittain siit\u00e4, ett\u00e4 maapallo ei ole t\u00e4ysin py\u00f6re\u00e4 \u2013 se on hieman litistynyt navoilla. Painovoimaan vaikuttavat my\u00f6s korkeat vuoret ja syv\u00e4t meren syv\u00e4nteet sek\u00e4 merien ja kallioper\u00e4n paksuus ja tiheys.<\/p>\n<figure class=\"wp-block-image size-large\" data-width=\"3000\" data-credit=\"ESA\/HPF\/DLR\" data-detail-url=\"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2011\/03\/New_GOCE_geoid2\" data-licence=\"ESA Standard Licence\" data-licence-url=\"https:\/\/www.esa.int\/ESA_Multimedia\/Terms_and_conditions_of_use_of_images_and_videos_available_on_the_esa_website\"><img decoding=\"async\" loading=\"lazy\" style=\"max-width:100%;height:auto\" src=\"https:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2011\/03\/new_goce_geoid2\/17882511-2-eng-GB\/New_GOCE_geoid.jpg\" alt=\"New GOCE geoid\"><figcaption>Uusi GOCE-geoidi<\/figcaption><\/figure>\n<p>Kun GOCE lent\u00e4\u00e4 eri painovoimakenttien yli, avaruusalus heilahtaa yl\u00f6s ja alas, ja sen mittalaitteet rekister\u00f6iv\u00e4t n\u00e4m\u00e4 muutokset sen lentoradassa. T\u00e4llaiset tarkat mittaukset ovat mahdollistuneet aluksen matalan kiertoradan ja virtaviivaisen, aerodynaamisen rakenteen ansiosta, mink\u00e4 vuoksi sille on annettu lempinimi \u2018avaruuden Ferrari\u2019. T\u00e4m\u00e4 ainutlaatuinen satelliitti on my\u00f6s eritt\u00e4in vakaa, sill\u00e4 siin\u00e4 ei ole lainkaan liikkuvia osia, joita k\u00e4ytet\u00e4\u00e4n usein muissa avaruusaluksissa.<\/p>\n<p>GOCE:n tietoja on k\u00e4ytetty merivirtausten, merenpinnan muutosten, maanpinnan korkeuden sek\u00e4 maapallon kivikuoren kerrostuneen rakenteen tutkimiseen. Se havaitsi jopa avaruudessa puhaltavia tuulia ja \u00e4\u00e4niaaltoja, jotka eteniv\u00e4t yl\u00f6sp\u00e4in ilmakeh\u00e4n l\u00e4pi 11. maaliskuuta 2011 Japania koetelleen valtavan maanj\u00e4ristyksen j\u00e4lkeen. Ehk\u00e4 t\u00e4rkein tulos on ollut eritt\u00e4in tarkka malli (ns. \u2018geoidi\u2019) maapallon painovoimasta. Geoidi kuvaa, milt\u00e4 maapallo n\u00e4ytt\u00e4isi, jos painovoima olisi sama kaikkialla sen pinnalla, jolloin vesi ei virtaisi yhdest\u00e4 pisteest\u00e4 toiseen.<\/p>","protected":false},"excerpt":{"rendered":"<p>After more than four years in orbit, ESA\u2019s GOCE mission is nearing its end. In mid-October, the satellite will run out of fuel and its orbit will begin to decay. [&hellip;]<\/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\/2008\/03\/goce_in_orbit4\/18246217-2-eng-GB\/GOCE_in_orbit.jpg","esa_banner_description":"GOCE in orbit","esa_banner_credit":"ESA\/AOES Medialab","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2008\/03\/GOCE_in_orbit4","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":[26],"tags":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-624","post","type-post","status-publish","format-standard","hentry","category-news"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/624","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=624"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/624\/revisions"}],"predecessor-version":[{"id":4591,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/624\/revisions\/4591"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/media?parent=624"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/categories?post=624"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/tags?post=624"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/panel?post=624"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/language?post=624"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/age?post=624"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/duration?post=624"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/resource_type?post=624"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/audience?post=624"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/wf_post_folders?post=624"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}