China\u2019s Giant Underground Neutrino Observatory Just Released Its First Results\u2014And They\u2019re Promising<\/p>\n
Hidden beneath the hills of southern China, the JUNO observatory shows promise in solving neutrino mysteries<\/p>\n
By Jeanna Bryner<\/a> edited by Claire Cameron<\/a><\/p>\n JUNO\u2019s central detector is filled with scintillating fluid and surrounded by photomultiplier tubes (shown here).<\/p>\n Yuexiang Liu\/JUNO Collaboration<\/p>\n Trillions of neutrinos whiz through our bodies every day, pulsing from the sun, outer space and deep beneath Earth. Yet these elusive subatomic particles have proven difficult to study. That could soon change, however. Buried 700 meters beneath the rolling hills of southern China, an enormous neutrino observatory called JUNO<\/a> has released its first results after a mere 59 days of operation. And so far, they are very promising, physicists say.<\/p>\n \u201cThe physics result is already world-leading in the areas that it touches,\u201d says particle physicist Juan Pedro Ochoa-Ricoux of the University of California, Irvine, who co-leads a team on JUNO.<\/p>\n \u201cIn particular, we measured two neutrino oscillation parameters, and that measurement is already for both parameters the best in the world,\u201d he says. The results<\/a> were published in two separate preprints on arXiv.org<\/a>.<\/p>\n On supporting science journalism<\/p>\n If you’re enjoying this article, consider supporting our award-winning journalism by subscribing<\/a>. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.<\/p>\n JUNO\u2014short for Jiangmen Underground Neutrino Observatory\u2014has been tasked with a tall order: determine the ordering of masses of the three types of neutrino. In other words, do they follow a \u201cnormal mass ordering,\u201d where the first flavor of neutrino is the lightest and the third the heaviest, or an inverted one, in which the third neutrino mass state is the lightest?<\/p>\n The answer to this question holds myriad implications, from informing other experiments to uncovering new physics to explaining certain cosmological mysteries. That\u2019s because despite being such lightweights, neutrinos are so incredibly numerous that they may play an outsized role in the distribution of matter in the universe.<\/p>\n JUNO\u2019s spherical detector, which is akin to a 13-story-tall fishbowl, primarily measures so-called electron antineutrinos spewing from the nearby Yangjian and Taishan nuclear plants. When the particles strike a proton inside the detector, a reaction triggers two light flashes that ping photomultiplier tubes and get converted into electrical signals.<\/p>\n The new measurements from these neutrino-proton collisions are now considered the most precise for two oscillation parameters, which act as proxies for differences in their mass, according to Ochoa-Ricoux.<\/p>\n \u201cIt is the first time we\u2019ve turned on a scientific instrument like JUNO that we\u2019ve been working on for over a decade. It\u2019s just tremendously exciting,\u201d Ochoa-Ricoux says. \u201cAnd then to see that we\u2019re able to already do world-leading measurements with it, even with such a small amount of data, that\u2019s also really exciting.\u201d<\/p>\n Still, the physicists will need years\u2019 worth of neutrino detections to answer the mass-ordering conundrum.<\/p>\n It\u2019s Time to Stand Up for Science<\/p>\n If you enjoyed this article, I\u2019d like to ask for your support. 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I hope you\u2019ll support us in that mission.<\/p>\n","protected":false},"excerpt":{"rendered":"November 26, 2025 2 min read Add Us On GoogleAdd SciAm China\u2019s Giant Underground Neutrino Observatory Just Released…\n","protected":false},"author":2,"featured_media":320855,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[24],"tags":[49,48,314,66],"class_list":{"0":"post-320854","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-physics","8":"tag-ca","9":"tag-canada","10":"tag-physics","11":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/320854","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=320854"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/320854\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/320855"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=320854"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=320854"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=320854"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"A](\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2025\/12\/juno-photomultiplier-tubes-neutrinos-web.jpg\")
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