{"id":1106,"date":"2006-01-20T13:10:00","date_gmt":"2006-01-20T12:10:00","guid":{"rendered":"https:\/\/kids.esa.int\/neptune\/"},"modified":"2026-10-08T00:36:04","modified_gmt":"2026-10-07T22:36:04","slug":"neptune","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fi\/neptune\/","title":{"rendered":"Neptunus"},"content":{"rendered":"
\n

Neptunuksen l\u00f6ysi vuonna 1846 Johann Galle, Berliinin observatorion t\u00e4htitieteilij\u00e4. Galle tiesi, mist\u00e4 etsi\u00e4, ranskalaisen matemaatikon Urbain Le Verrierin laskelmien ansiosta. Sek\u00e4 Le Verrier ett\u00e4 englantilainen John Adams olivat tulleet siihen tulokseen, ett\u00e4 n\u00e4kym\u00e4t\u00f6n planeetta vaikutti Uranukseen vetovoimallaan, mik\u00e4 sai sen hidastumaan tai kiihtym\u00e4\u00e4n.<\/p>\n<\/div>\n

Neptunus osoittautui l\u00e4hes identtiseksi kaksoseksi Uranuksen kanssa. Se on 57 kertaa Maata suurempi, mutta py\u00f6rii varsin nopeasti \u2013 yksi p\u00e4iv\u00e4 kest\u00e4\u00e4 vain 16 tuntia 7 minuuttia. Sen keskim\u00e4\u00e4r\u00e4inen et\u00e4isyys Auringosta on noin 4 500 miljoonaa kilometri\u00e4, ja yksi vuosi Neptunuksella kest\u00e4\u00e4 l\u00e4hes 165 maapallon vuotta.<\/p>\n

Uranuksen tavoin sen ilmakeh\u00e4 koostuu vedyst\u00e4, heliumista ja metaanista. Sen sisus koostuu j\u00e4\u00e4st\u00e4, ja sill\u00e4 saattaa olla kivinen ydin. Vaikka ilmakeh\u00e4 on eritt\u00e4in kylm\u00e4 (-220 astetta C), sinisell\u00e4 planeetalla puhaltaa eritt\u00e4in voimakkaita tuulia ja raivoaa myrskyj\u00e4. Voyager 2 kuvasi valtavan, Maan kokoisen t\u00e4pl\u00e4n.<\/p>\n

Neptunuksella on v\u00e4hint\u00e4\u00e4n viisi tummaa, kapeaa rengasta (jotka on nimetty Gallen, Le Verrierin, Adamsin ja muiden planeetan l\u00f6yt\u00e4miseen osallistuneiden henkil\u00f6iden mukaan).<\/p>\n

Sill\u00e4 on 13 tunnettua kuuta. Selv\u00e4sti suurin niist\u00e4 on Triton, j\u00e4\u00e4inen taivaankappale, joka on suurempi kuin Pluto. Triton on eritt\u00e4in kylm\u00e4, joten sen ohut ilmakeh\u00e4 on j\u00e4\u00e4tynyt kiinni pintaan. Siell\u00e4 on kuitenkin monia aktiivisia j\u00e4\u00e4vuoria, joista purkautuu kaasu- ja p\u00f6lypilvi\u00e4. Triton on poikkeuksellinen my\u00f6s siksi, ett\u00e4 se kiert\u00e4\u00e4 Neptunusta \u201cv\u00e4\u00e4r\u00e4\u00e4n suuntaan\u201d (id\u00e4st\u00e4 l\u00e4nteen). Se n\u00e4ytt\u00e4\u00e4 joutuneen Neptunuksen painovoiman vangiksi kauan sitten.<\/p>","protected":false},"excerpt":{"rendered":"

Neptune was discovered in 1846 by Johann Galle, an astronomer at the Berlin Observatory. Galle knew where to look because of calculations by French mathematician Urbain Le Verrier. Both Le […]<\/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\/2000\/12\/neptune2\/17866082-3-eng-GB\/Neptune.jpg","esa_banner_description":"Neptune","esa_banner_credit":"ESA","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2000\/12\/Neptune2","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":[10,11,12],"tags":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-1106","post","type-post","status-publish","format-standard","hentry","category-learn","category-our-universe","category-planets-and-moons"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/1106","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=1106"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/1106\/revisions"}],"predecessor-version":[{"id":2249,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/1106\/revisions\/2249"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/media?parent=1106"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/categories?post=1106"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/tags?post=1106"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/panel?post=1106"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/language?post=1106"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/age?post=1106"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/duration?post=1106"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/resource_type?post=1106"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/audience?post=1106"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/wf_post_folders?post=1106"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}