{"id":1123,"date":"2004-12-03T10:13:00","date_gmt":"2004-12-03T09:13:00","guid":{"rendered":"https:\/\/kids.esa.int\/how_do_we_observe_the_earth\/"},"modified":"2026-10-08T00:36:15","modified_gmt":"2026-10-07T22:36:15","slug":"how_do_we_observe_the_earth","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fi\/how_do_we_observe_the_earth\/","title":{"rendered":"Miten tarkkailemme Maata?"},"content":{"rendered":"
\n

Monien vuosisatojen ajan ainoa tapa saada hyv\u00e4 n\u00e4kym\u00e4 laajalle alueelle oli kiivet\u00e4 korkeammalle maastoon. Sitten ilmapallojen ja lentokoneiden keksiminen helpotti maapallon havainnointia huomattavasti.<\/p>\n<\/div>\n

Avaruusajan aikana satelliitteja on k\u00e4ytetty yh\u00e4 enemm\u00e4n maapallomme kaikkien osa-alueiden tutkimiseen.<\/p>\n

Koska ne tarkkailevat Maata kaukaa, niit\u00e4 kutsutaan usein \u201ckaukokartoitussatelliiteiksi\u201d.<\/p>\n

Yksityiskohtaisimmat kuvat maapallon pinnasta ja ilmakeh\u00e4st\u00e4 l\u00e4hetet\u00e4\u00e4n matalalla kiertoradalla olevista satelliiteista, joiden reitti kulkee pohjois- ja etel\u00e4navan yli.<\/p>\n

Kun Maa py\u00f6rii niiden alla, n\u00e4m\u00e4 satelliitit pystyv\u00e4t kuvaamaan koko planeetan \u2013 kaistalta kaistalta \u2013 muutaman p\u00e4iv\u00e4n v\u00e4lein.<\/p>\n

\"Envisat,
Envisat, taiteilijan n\u00e4kemys<\/figcaption><\/figure>\n

Polaarikiertoradalla liikkuvat satelliitit tutkivat j\u00e4\u00e4- ja lumipeitett\u00e4, maank\u00e4ytt\u00f6\u00e4, ilman ja veden pilaantumista sek\u00e4 paikallista s\u00e4\u00e4t\u00e4. ESA:n polaarikiertoradalla liikkuvat satelliitit ovat Euroopan kaukokartoitussatelliitti (ERS-2) ja ymp\u00e4rist\u00f6satelliitti Envisat.<\/p>\n

Muut avaruusalukset tarkkailevat jatkuvasti samaa osaa maapallosta kiert\u00e4ess\u00e4\u00e4n 36 000 km:n korkeudella p\u00e4iv\u00e4ntasaajan yl\u00e4puolella. T\u00e4m\u00e4 antaa niille laajemman n\u00e4kym\u00e4n, mutta se tarkoittaa my\u00f6s, ett\u00e4 ne eiv\u00e4t n\u00e4e maapalloa yht\u00e4 yksityiskohtaisesti.<\/p>\n

Eurooppa on t\u00e4h\u00e4n menness\u00e4 l\u00e4hett\u00e4nyt kahdeksan Meteosat-nimist\u00e4 s\u00e4\u00e4satelliittia t\u00e4llaiseen \u201cgeostationaariseen\u201d kiertoradalle.<\/p>","protected":false},"excerpt":{"rendered":"

For many centuries, the only way to obtain a good view of a large area was to climb to higher ground. Then the invention of balloons and aircraft made Earth […]<\/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\/07\/the_world_seen_by_envisat_s_meris2\/17870967-2-eng-GB\/The_world_seen_by_Envisat_s_MERIS.jpg","esa_banner_description":"The world seen by Envisat 's MERIS","esa_banner_credit":"ESA 2004","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2004\/07\/The_world_seen_by_Envisat_s_MERIS2","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":[2],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-1123","post","type-post","status-publish","format-standard","hentry","category-earth","category-learn","category-natural-disasters","tag-background-article"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/1123","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=1123"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/1123\/revisions"}],"predecessor-version":[{"id":4859,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/1123\/revisions\/4859"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/media?parent=1123"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/categories?post=1123"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/tags?post=1123"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/panel?post=1123"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/language?post=1123"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/age?post=1123"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/duration?post=1123"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/resource_type?post=1123"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/audience?post=1123"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/wf_post_folders?post=1123"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}