{"id":95878,"date":"2024-06-25T11:33:50","date_gmt":"2024-06-25T09:33:50","guid":{"rendered":"https:\/\/www.astb.se\/cassiopeiabloggen\/?p=95878"},"modified":"2024-06-25T17:33:03","modified_gmt":"2024-06-25T15:33:03","slug":"nr-44-2024","status":"publish","type":"post","link":"https:\/\/www.astb.se\/cassiopeiabloggen\/2024\/06\/25\/nr-44-2024\/","title":{"rendered":"Nr 44 2024"},"content":{"rendered":"\n

Jupiters r\u00f6da fl\u00e4ck i dag \u00e4r inte Cassinis fl\u00e4ck<\/h2>\n\n\n\n

Hoppsan! Ibland sl\u00e5s gamla astronomiska sj\u00e4lvklarheter omkull. I (n\u00e4stan) alla b\u00f6cker st\u00e5r att den fl\u00e4ck Cassini uppt\u00e4ckte p\u00e5 Jupiter redan 1665 skulle vara den stora r\u00f6da fl\u00e4ck vi fortfarande ser i dag – en gigantisk storm – med en 350-\u00e5rig historia. Men det tror vi inte l\u00e4ngre.<\/p>\n\n\n\n

Den Stora R\u00f6da Fl\u00e4cken aka The Great Red Spot aka GRS \u00e4r den st\u00f6rsta k\u00e4nda meteorologiska virvelformationen i planetsystemets atmosf\u00e4rer. Jupiterforskaren Agust\u00edn S\u00e1nchez-Lavega<\/strong> vid University of the Basque Country i Bilbao, Spanien, tror inte att fl\u00e4cken \u00e4r densamma som Cassini uppt\u00e4ckte. Denna f\u00f6rsvann ur astronomernas blickf\u00e5ng 1713 och f\u00f6rst 1831 s\u00e5gs dagens r\u00f6da fenomen, p\u00e5 n\u00e4stan samma latitud p\u00e5 planeten som Cassinis.<\/p>\n\n\n\n

Sedan slutet av 1800-talet har fl\u00e4cken b\u00e5de blivit mindre och rundare och dess uppkomst \u00e4r fortfarande g\u00e5tfull. Mycket skedde i studierna av fl\u00e4cken med de allt st\u00f6rre och skarpare 1800-talsteleskopen: Det ins\u00e5gs att fl\u00e4cken inte var vulkanisk, den var inte f\u00f6rankrad p\u00e5 Jupiters eventuellt f\u00f6rekommande fasta kropp, fl\u00e4cken fl\u00f6t i atmof\u00e4ren. Vid ett tillf\u00e4llen “jagades” fl\u00e4cken av en mindre m\u00f6rkare molnformation som l\u00e5g p\u00e5 samma latitud. Passagen inv\u00e4ntades med sp\u00e4nning, men den mindre fl\u00e4cken fegade och rundade den r\u00f6da fl\u00e4cken vid kanten s\u00f6der om.<\/p>\n\n\n

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Teckning av Giovanni Cassini fr\u00e5n 1677, d\u00e5 fl\u00e4cken fortfarande var fullt synlig.<\/em><\/figcaption><\/figure><\/div>\n\n\n

Genom Jupitersonden Junos m\u00e4tningar vet vi att fl\u00e4cken i dag b\u00e5de \u00e4r relativt tunn och absolut inte djup..<\/p>\n\n\n\n

Bakom studien i dag <\/a>ligger b\u00e5de historiskt k\u00e4llmaterial men ocks\u00e5 numeriska ber\u00e4kningar med hj\u00e4lp av superdatorer. Vad vi ser \u00e4r resultat av komplexa meteorologiska samverkande cyklon- och cellfenomen i gasj\u00e4ttens yttre. Fr\u00e5gan \u00e4r om dagens fl\u00e4ck kommer att \u00f6verleva s\u00e4rskilt l\u00e4nge till (astronomiskt sett). I rapportens Abstract st\u00e5r f\u00f6ljande:<\/p>\n\n\n\n

“Numerical simulations rule out that the GRS formed by the merging of vortices or by a superstorm, but most likely formed from a flow disturbance between the two opposed Jovian zonal jets north and south of it. If so, the early GRS should have had a low tangential velocity so that its rotation velocity has increased over time as it has shrunk.”<\/p>\n\n\n\n

Nedan ett foto fr\u00e5n Juno-sonden 2018. Bildk\u00e4lla: Enhanced Image by Gerald Eichstadt and Sean Doran (CC BY-NC-SA) based on images provided Courtesy of NASA\/JPL-Caltech\/SwRI\/MSSS.<\/p>\n\n\n\n

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Tidiga beskrivningar av fl\u00e4cken: a en m\u00e5lning av Donato Creti fr\u00e5n 1711, b och c med den avl\u00e5nga fl\u00e4cken fr\u00e5n slutet av 1800-talet (Trouvelet och Elger): <\/p>\n\n\n\n

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<\/p>\n\n\n\n

\u00c4ven Webb-teleskopet har specialstuderat r\u00f6da fl\u00e4cken<\/h2>\n\n\n\n

En rad nya intrikata strukturer \u00f6ver Jupiters r\u00f6da fl\u00e4ck har uppt\u00e4ckts av JWST, enligt en pressrelis i dag<\/a> (25.6).<\/p>\n\n\n\n

Forskarna s\u00e4ger sj\u00e4lva att de f\u00f6rv\u00e4ntat sig en ganska tr\u00e5kig (“dull”) region \u00f6ver fl\u00e4cken, men s\u00e5 \u00e4r det inte. Mysteriet djupnar.<\/p>\n\n\n

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Fr\u00e5n pressrelisen denna bildinfo: New observations of the Great Red Spot on Jupiter have revealed that the planet\u2019s atmosphere above and around the infamous storm is surprisingly interesting and active. This graphic shows the region observed by Webb \u2014 first its location on a NIRCam image of the whole planet (left), and the region itself (right), imaged by Webb\u2019s Near-InfraRed Spectrograph (NIRSpec). The NIRSpec image is stitched together from six NIRSpec Integral Field Unit images taken in July 2022, each around 300 square kilometres, and shows infrared light emitted by hydrogen molecules in Jupiter\u2019s ionosphere. These molecules lie over 300 kilometres above the clouds of the storm, where light from the Sun ionises the hydrogen and stimulates this infrared emission. In this image, redder colours display the hydrogen emission from these high altitudes in the planet\u2019s ionosphere. Bluer colours show infrared light from lower altitudes, including cloud-tops in the atmosphere and the very prominent Great Red Spot.  Jupiter is distant from the Sun and therefore receives a uniform, low level of daylight, meaning that most of the planet\u2019s surface is relatively dim at these infrared wavelengths \u2014 especially compared to the emission from molecules near the poles, where Jupiter\u2019s magnetic field is especially strong. Contrary to the researchers\u2019 expectations that this area would therefore look homogeneous in nature, it hosts a variety of intricate structures, including dark arcs and bright spots, across the entire field of view. [Image Description: A graphic with two panels. The left side is an infrared image of the planet Jupiter, labelled \u201cWebb\/NIRCam\u201d. The planet is shown in multiple colours, especially at the poles, and on the Great Red Spot, visible as a circular storm at the planet\u2019s bottom-right. The Spot is surrounded by a jagged rectangle highlight. The right side shows a close-in image of that area in different colours, labelled \u201cWebb\/NIRSpec\u201d. <\/em><\/figcaption><\/figure><\/div>\n\n\n

Lundakatastrofen i Forskning & Framsteg<\/em><\/h2>\n\n\n\n

FoF:s granskning finns h\u00e4r<\/a> f\u00f6r tidskriftens prenumeranter. Texten skriven av Anna Davour.<\/strong><\/p>\n\n\n\n

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M\u00e5ste det vara s\u00e5 inom astronomin som Harlow Shapley<\/strong> en g\u00e5ng p\u00e5pekade att det n\u00e4rmast \u00e4r normalt att en doktorand ska drabbas av en nervkollaps? Vi trodde vi hade kommit l\u00e4ngre.<\/p>\n","protected":false},"excerpt":{"rendered":"

Jupiters r\u00f6da fl\u00e4ck i dag \u00e4r inte Cassinis fl\u00e4ck Hoppsan! Ibland sl\u00e5s gamla astronomiska sj\u00e4lvklarheter omkull. I (n\u00e4stan) alla b\u00f6cker st\u00e5r att den fl\u00e4ck Cassini uppt\u00e4ckte p\u00e5 Jupiter redan 1665 skulle vara den stora r\u00f6da fl\u00e4ck vi fortfarande ser i dag – en gigantisk storm – med en 350-\u00e5rig historia. Men det tror vi inte… L\u00e4s mer »Nr 44 2024<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"rop_custom_images_group":[],"rop_custom_messages_group":[],"rop_publish_now":"initial","rop_publish_now_accounts":[],"rop_publish_now_history":[],"rop_publish_now_status":"pending","neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"","neve_meta_content_width":0,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","footnotes":""},"categories":[3],"tags":[],"_links":{"self":[{"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/posts\/95878"}],"collection":[{"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/comments?post=95878"}],"version-history":[{"count":21,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/posts\/95878\/revisions"}],"predecessor-version":[{"id":95910,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/posts\/95878\/revisions\/95910"}],"wp:attachment":[{"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/media?parent=95878"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/categories?post=95878"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.astb.se\/cassiopeiabloggen\/wp-json\/wp\/v2\/tags?post=95878"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}