{"id":877,"date":"2005-06-30T09:24:00","date_gmt":"2005-06-30T07:24:00","guid":{"rendered":"https:\/\/kids.esa.int\/esa_s_gravity_explorer\/"},"modified":"2026-10-08T00:33:17","modified_gmt":"2026-10-07T22:33:17","slug":"esa_s_gravity_explorer","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fi\/esa_s_gravity_explorer\/","title":{"rendered":"ESAn Gravity Explorer"},"content":{"rendered":"
\n

ESA:n uuden tutkimuksen mukaan 26. joulukuuta 2004 tapahtunut Sumatran maanj\u00e4ristys ei ainoastaan tuhonnut valtavaa aluetta, vaan se my\u00f6s muutti hieman kyseisen alueen painovoimaa.<\/p>\n<\/div>\n

Kun Intian valtameren pohja siirtyi maanj\u00e4ristyksen aikana 1000 km:n pituisen siirroslinjan varrella, se muodosti 6 metri\u00e4 korkean ulkoneman. T\u00e4m\u00e4 valtava kallioliike muutti v\u00e4litt\u00f6m\u00e4sti paikallista painovoimaa.<\/p>\n

T\u00e4m\u00e4 ei ole mitenk\u00e4\u00e4n ep\u00e4tavallista. Satelliittitietojen perusteella laaditut kartat osoittavat, ett\u00e4 painovoiman voimakkuus vaihtelee paikasta toiseen. Yksi syy t\u00e4h\u00e4n on Maan py\u00f6riminen. Kun planeetta py\u00f6rii, se pullistuu ulosp\u00e4in p\u00e4iv\u00e4ntasaajalla. Koska Maa on p\u00e4iv\u00e4ntasaajalla 42 km leve\u00e4mpi, painovoima on siell\u00e4 heikompi kuin navoilla.<\/p>\n

My\u00f6s korkeat vuoret, syv\u00e4t meren syv\u00e4nteet ja maapallon sis\u00e4ll\u00e4 olevat erilaiset kivilajit vaikuttavat asiaan. Jopa vuorovedet, merivirrat ja sulavat j\u00e4\u00e4peitteet saavat painovoiman arvon vaihtelemaan.<\/p>\n

\"Artist's
Taiteilijan n\u00e4kemys GOCE-satelliitista<\/figcaption><\/figure>\n

T\u00e4ll\u00e4 hetkell\u00e4 t\u00e4llaisia pieni\u00e4 painovoiman muutoksia on vaikea mitata, mutta tilanne muuttuu, kun ESA:n Gravity Field and Ocean Circulation Explorer (GOCE) -satelliitti laukaistaan ensi vuonna.<\/p>\n

T\u00e4m\u00e4 herkk\u00e4 avaruusalus tutkii painovoimaa eritt\u00e4in yksityiskohtaisesti. Kun alus lent\u00e4\u00e4 voimakkaamman ja heikomman painovoiman alueiden yli, se heiluu yl\u00f6s ja alas, ja sen mittalaitteet mittaavat reitin varrella muuttuvaa painovoimakentt\u00e4\u00e4.<\/p>\n

T\u00e4m\u00e4n avulla tutkijat voivat mitata, kuinka paljon materiaalia liikkuu, joko \u00e4killisesti maanj\u00e4ristyksen yhteydess\u00e4 tai v\u00e4hitellen, kuten sulavan j\u00e4\u00e4peitteen tapauksessa. Tiedot auttavat jopa paljastamaan ilmastonmuutokseen liittyvi\u00e4 muutoksia merivirtauksissa.<\/p>","protected":false},"excerpt":{"rendered":"

According to a new ESA study, the Sumatran earthquake of 26 December 2004 not only devastated a huge area, but it slightly altered the gravity of that area. When 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\/2005\/04\/ers-2_composite_highlighting_tsunami_damage3\/17891576-2-eng-GB\/ERS-2_composite_highlighting_tsunami_damage.jpg","esa_banner_description":"ERS-2 composite highlighting tsunami damage","esa_banner_credit":"ESA","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2005\/04\/ERS-2_composite_highlighting_tsunami_damage3","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":[42,10,59],"tags":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-877","post","type-post","status-publish","format-standard","hentry","category-earth","category-learn","category-natural-disasters"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/877","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=877"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/877\/revisions"}],"predecessor-version":[{"id":4715,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/877\/revisions\/4715"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/media?parent=877"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/categories?post=877"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/tags?post=877"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/panel?post=877"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/language?post=877"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/age?post=877"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/duration?post=877"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/resource_type?post=877"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/audience?post=877"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/wf_post_folders?post=877"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}