{"id":661,"date":"2008-07-04T09:36:00","date_gmt":"2008-07-04T07:36:00","guid":{"rendered":"https:\/\/kids.esa.int\/can_et_hear_the_sounds_of_earth\/"},"modified":"2026-10-08T00:30:51","modified_gmt":"2026-10-07T22:30:51","slug":"can_et_hear_the_sounds_of_earth","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fi\/can_et_hear_the_sounds_of_earth\/","title":{"rendered":"Voiko ET kuulla Maan \u00e4\u00e4ni\u00e4?"},"content":{"rendered":"<div class=\"lede\">\n<p>ESAn nelj\u00e4 Cluster-avaruusluotainta ovat havainneet, ett\u00e4 Maalla ja muilla planeetoilla on tapana huutaa \u201cT\u00e4\u00e4ll\u00e4 ollaan!\u201d muulle galaksille. Planeettojen l\u00e4hett\u00e4mi\u00e4 viestej\u00e4 voidaan kuitenkin kuulla ja ymm\u00e4rt\u00e4\u00e4 vain suurten radioteleskooppien avulla. Maan luonnollisia radiosignaaleja vastaanottava muukalaisrotu kuulee sarjan piipityksi\u00e4 ja vihellyksi\u00e4, v\u00e4h\u00e4n kuin kuuntelisi R2-D2:ta, T\u00e4htien sodan robottia.<\/p>\n<\/div>\n<p>T\u00e4ll\u00e4 hetkell\u00e4 edes nykyaikaisimmat teleskoopit eiv\u00e4t ole riitt\u00e4v\u00e4n tehokkaita havaitsemaan kaukaisten t\u00e4htien ymp\u00e4rill\u00e4 kiert\u00e4vi\u00e4 Maan kokoisia planeettoja. Sama ongelma koskee my\u00f6s muukalaisastronomia \u2013 Maan etsiminen olisi kuin neulan etsimist\u00e4 hein\u00e4suovasta. Maapallomme radiopurkaukset \u2013 jotka ovat 10 000 kertaa voimakkaampia kuin voimakkain sotilastutkasignaali \u2013 paljastavat kuitenkin selv\u00e4sti Maan olemassaolon.<\/p>\n<figure class=\"wp-block-image size-natural\" data-width=\"400\" data-credit=\"ESA\" data-detail-url=\"https:\/\/www.esa.int\/Media\/Animations\/Auroral-2HQ\" 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\/media\/animations\/auroral-2hq\/9257-5-eng-GB\/Auroral-2HQ.jpg\" alt=\"\"><\/figure>\n<p>Tutkijat ovat tienneet jo 1970-luvulta l\u00e4htien, ett\u00e4 magneettikent\u00e4n omaavat planeetat (mukaan lukien Maa, Jupiter ja Saturnus) l\u00e4hett\u00e4v\u00e4t voimakkaita radiosignaaleja. S\u00e4teilut syntyv\u00e4t kunkin planeetan yl\u00e4puolella samoista aurinkohiukkasista, jotka saavat revontulet valaisemaan taivaan alapuolella. T\u00e4h\u00e4n asti t\u00e4htitieteilij\u00e4t olivat olettaneet, ett\u00e4 n\u00e4m\u00e4 radioaallot levi\u00e4v\u00e4t avaruuteen yh\u00e4 laajenevassa kartiossa, kuten taskulampun valo. Cluster-satelliitin ansiosta tied\u00e4mme nyt, ett\u00e4 t\u00e4m\u00e4 ei pid\u00e4 paikkaansa.<\/p>\n<p>Kun radioaaltojen purskeet pyyhk\u00e4isiv\u00e4t vuorotellen kunkin avaruusaluksen yli, tutkijat pystyiv\u00e4t laskemaan niiden koon ja sijainnin. On k\u00e4ynyt ilmi, ett\u00e4 signaalit kulkevat avaruudessa kapeana s\u00e4teen\u00e4. T\u00e4m\u00e4n ansiosta on paljon helpompaa selvitt\u00e4\u00e4 tarkasti, mist\u00e4 ne tulevat. Tulevaisuudessa saatamme l\u00f6yt\u00e4\u00e4 vieraita maailmoja kuuntelemalla niiden piipityksi\u00e4 ja vihellyksi\u00e4.<\/p>","protected":false},"excerpt":{"rendered":"<p>ESA\u2019s four Cluster spacecraft have found that Earth and other planets have a way of shouting \u201cI\u2019m here!\u201d to the rest of the Galaxy. However, the messages from the planets [&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\/2002\/08\/the_cluster_constellation\/17863826-3-eng-GB\/The_Cluster_constellation.jpg","esa_banner_description":"The Cluster constellation","esa_banner_credit":"ESA","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2002\/08\/The_Cluster_constellation","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":[14,10,13],"tags":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-661","post","type-post","status-publish","format-standard","hentry","category-are-we-alone","category-learn","category-life-in-space"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/661","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=661"}],"version-history":[{"count":5,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/661\/revisions"}],"predecessor-version":[{"id":4616,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/661\/revisions\/4616"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/media?parent=661"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/categories?post=661"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/tags?post=661"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/panel?post=661"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/language?post=661"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/age?post=661"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/duration?post=661"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/resource_type?post=661"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/audience?post=661"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/wf_post_folders?post=661"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}