{"id":1005,"date":"2004-11-15T13:50:00","date_gmt":"2004-11-15T12:50:00","guid":{"rendered":"https:\/\/kids.esa.int\/what_is_space\/"},"modified":"2026-10-08T00:34:45","modified_gmt":"2026-10-07T22:34:45","slug":"what_is_space","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fi\/what_is_space\/","title":{"rendered":"Mit\u00e4 on avaruus?"},"content":{"rendered":"<div class=\"lede\">\n<p>Avaruudessa kukaan ei kuule huutoasi. T\u00e4m\u00e4 johtuu siit\u00e4, ett\u00e4 avaruudessa ei ole ilmaa \u2013 se on tyhji\u00f6. \u00c4\u00e4niaallot eiv\u00e4t voi kulkea tyhji\u00f6ss\u00e4.<\/p>\n<\/div>\n<p>\u2018Avaruus\u2019 alkaa noin 100 km:n korkeudella maanpinnasta, miss\u00e4 planeettamme ymp\u00e4rill\u00e4 oleva ilmakeh\u00e4 loppuu. Koska ilmaa ei ole hajottamassa auringonvaloa ja luomassa sinist\u00e4 taivasta, avaruus n\u00e4ytt\u00e4\u00e4 mustalta peitolta, jota t\u00e4plitt\u00e4v\u00e4t t\u00e4hdet.<\/p>\n<p>Avaruutta pidet\u00e4\u00e4n yleens\u00e4 t\u00e4ysin tyhj\u00e4n\u00e4. T\u00e4m\u00e4 ei kuitenkaan pid\u00e4 paikkaansa. T\u00e4htien ja planeettojen v\u00e4liset valtavat aukot ovat t\u00e4ynn\u00e4 valtavia m\u00e4\u00e4ri\u00e4 harvaan levinnytt\u00e4 kaasua ja p\u00f6ly\u00e4. Jopa avaruuden tyhjimmiss\u00e4 osissa on v\u00e4hint\u00e4\u00e4n muutama sata atomia tai molekyyli\u00e4 kuutiometriss\u00e4.<\/p>\n<p>Avaruus on my\u00f6s t\u00e4ynn\u00e4 monenlaista s\u00e4teily\u00e4, joka on vaarallista avaruuslent\u00e4jille. Suuri osa t\u00e4st\u00e4 infrapuna- ja ultraviolettis\u00e4teilyst\u00e4 on per\u00e4isin Auringosta. Korkeaenergiset r\u00f6ntgens\u00e4teet, gammas\u00e4teet ja kosmiset s\u00e4teet \u2013 hiukkaset, jotka liikkuvat l\u00e4hes valon nopeudella \u2013 saapuvat kaukaisista t\u00e4htij\u00e4rjestelmist\u00e4.<\/p>","protected":false},"excerpt":{"rendered":"<p>In space, no one can hear you scream. This is because there is no air in space \u2013 it is a vacuum. Sound waves cannot travel through a vacuum. &#8216;Outer [&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\/2004\/12\/earth_from_space2\/17871152-2-eng-GB\/Earth_from_space.jpg","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\/Earth_from_space2","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":[10,11,19],"tags":[2],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-1005","post","type-post","status-publish","format-standard","hentry","category-learn","category-our-universe","category-story-of-the-universe","tag-background-article"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/1005","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=1005"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/1005\/revisions"}],"predecessor-version":[{"id":2148,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/1005\/revisions\/2148"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/media?parent=1005"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/categories?post=1005"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/tags?post=1005"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/panel?post=1005"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/language?post=1005"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/age?post=1005"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/duration?post=1005"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/resource_type?post=1005"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/audience?post=1005"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/wf_post_folders?post=1005"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}