{"id":61998,"date":"2025-04-30T04:24:11","date_gmt":"2025-04-30T04:24:11","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/61998\/"},"modified":"2025-04-30T04:24:11","modified_gmt":"2025-04-30T04:24:11","slug":"scientists-detect-the-most-energetic-neutrino-ever-seen-and-they-have-no-idea-where-it-came-from","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/61998\/","title":{"rendered":"Scientists Detect the Most Energetic Neutrino Ever Seen and They Have No Idea Where It Came From"},"content":{"rendered":"

\"\"<\/a>Credit: ZME Science\/SORA.<\/p>\n

In the dark silence three kilometers beneath the Mediterranean Sea, a scientific machine called KM3NeT was slowly awakening. It had been built to capture ghostly messengers from deep space \u2014 particles so elusive that most would slip through the entire planet without a trace. But on February 13, 2023, something remarkable happened. A particle slammed into the water near the still-growing KM3NeT detector, triggering a signal so intense it lit up a third of the sensors.<\/p>\n

When Paschal Coyle, a physicist at the Centre for Particle Physics of Marseille, first tried to analyze it, his computer couldn\u2019t take it. \u201cWhen I first tried looking at this event, my program crashed,\u201d he told New Scientist<\/a>. What Coyle and his colleagues had found was not just another neutrino<\/a>. It was the most energetic neutrino ever observed, clocking in at an estimated 220 peta-electronvolts (PeV), an energy 16,000 times greater than anything created at the Large Hadron Collider.<\/p>\n

And it had traveled from somewhere far beyond our galaxy.<\/p>\n

A New Window to the Violent Universe<\/p>\n

\"Visual<\/a>Visual impression of the ultra-high energy neutrino event observed in KM3NeT\/ARCA. Credit: The KM3NeT Collaboration.<\/p>\n

Neutrinos are among the strangest particles in nature. First predicted in 1930 by Wolfgang Pauli and first detected in 1956, they carry no electric charge and have nearly no mass. They barely interact with matter. \u201cThey are special cosmic messengers that reveal the secrets of the most energetic phenomena in the universe,\u201d said Rosa Coniglione, a deputy spokesperson for KM3NeT at the time of the discovery in the Mediterranean.<\/p>\n

\"Modules<\/a>The digital optical modules are strung together to form the KM3Net neutrino telescope deep beneath the sea. Credit: The KM3NeT Collaboration.<\/p>\n

Normally, detecting a neutrino requires immense, creative experiments. KM3NeT is one of the boldest yet. Its giant arrays of spherical detectors, strung like beads on vertical lines anchored to the seafloor, use the Mediterranean\u2019s clear waters as a detection medium. When a neutrino finally smashes into an atom, it can create a muon \u2014 a heavier cousin of the electron \u2014 that speeds through the water faster than light can travel there. This produces a cone of bluish Cherenkov light<\/a>, like a sonic boom but made of photons, which the detectors can pick up.<\/p>\n

Despite being only a tenth complete, KM3NeT managed to capture the neutrino now known as KM3-230213A. \u201cThis first ever detection of a neutrino of hundreds of PeV opens a new chapter in neutrino astronomy,\u201d said Paschal Coyle.<\/p>\n

The find stunned researchers because nothing like it had ever been seen before. IceCube<\/a>, the South Pole\u2019s massive neutrino observatory, had previously detected cosmic neutrinos up to about 6 PeV. But this? This was on another scale entirely.<\/p>\n

\u201cIt was really surprising,\u201d said Rosa Coniglione. \u201cHow does a smaller detector that\u2019s been turned on for a shorter period of time see the rarest of them all, the highest-energy neutrino?\u201d wondered Naoko Kurahashi Neilson, a neutrino astronomer at Drexel University.<\/p>\n

Where Did It Come From?<\/p>\n

That is now the million \u2014 or perhaps trillion \u2014 dollar question.<\/p>\n

One possibility is that the neutrino was born in a cosmic particle accelerator like a blazar<\/a> \u2014 a galaxy with a supermassive black hole at its heart firing jets of particles directly toward Earth. IceCube had previously traced a lower-energy neutrino to such a blazar in 2018<\/a>. Yet, when KM3NeT researchers searched the sky region from which the 220 PeV neutrino arrived, they found no obvious source. <\/p>\n

\u201cThey did not identify any convincing source,\u201d said Shirley Li, a physicist at the University of California, Irvine.<\/p>\n

Another tantalizing idea is that the neutrino may be a cosmogenic neutrino. These are ultra-rare particles created when high-energy cosmic rays \u2014 protons and atomic nuclei flying across the universe at nearly the speed of light \u2014 slam into the cosmic microwave background radiation, the afterglow of the Big Bang.<\/p>\n

\"Neutrino <\/a>Credit: The KM3NeT Collaboration.<\/p>\n

\u201cIt is a very exciting possibility,\u201d said Li. Scientists have predicted the existence of cosmogenic neutrinos for decades, but no experiment had confirmed them. If KM3NeT\u2019s neutrino is cosmogenic, it would be the first direct evidence that these highest-energy neutrinos truly exist.<\/p>\n

Yet there is a catch. If cosmogenic neutrinos are out there, why hasn\u2019t IceCube already seen them? \u201cIt\u2019s challenging to say this event is from a cosmogenic flux,\u201d admitted Li.<\/p>\n

For now, the origin remains unknown. As Yuri Kovalev from the Max Planck Institute for Radio Astronomy put it, \u201cBy adding observations from other telescopes, we seek to connect the acceleration of cosmic rays, the production of neutrinos, and the role of supermassive black holes in shaping these energetic phenomena.\u201d<\/p>\n

Amazing and Mysterious<\/p>\n

Whether the neutrino came from a hidden blazar, a cosmic collision billions of light-years away, or something even stranger, the implications are profound. Neutrinos offer a pristine view of the universe\u2019s most violent processes. Unlike charged cosmic rays, neutrinos travel in straight lines, completely unaffected by magnetic fields. They also pass through gas, dust, and light without getting deflected or absorbed.<\/p>\n

\u201cThere are huge implications for science and astronomy,\u201d said Kurahashi Neilson. Neutrinos could, for instance, reveal how black holes grow and how stars explode. They might even explain why the universe is made of matter instead of antimatter. Some physicists suspect neutrinos may be key to uncovering physics beyond the Standard Model, the ruling theory of particles and forces.<\/p>\n

For instance, if neutrinos are Majorana particles<\/a> \u2014 particles that are their own antiparticles \u2014 it could explain why the Big Bang produced more matter than antimatter. \u201cIf neutrinos are their own antiparticle, that might explain where all the antimatter in the early universe went,\u201d said Ryan Nichol of University College London.<\/p>\n

And the cosmos itself could become a new kind of laboratory. \u201cThis is a whole new arena in which to look for deviations,\u201d said Li.<\/p>\n

KM3NeT is still under construction. Once completed around 2029, it will fill more than one cubic kilometer of deep-sea volume with 230 detection lines, each studded with optical modules. Scientists also have their eyes on other projects, like the Pacific Ocean Neutrino Experiment<\/a> off Canada\u2019s coast, and continued work at IceCube\u2019s upgraded observatory.<\/p>\n

Until then, researchers will wait for more ghostly signals from the abyss\u2014tiny flashes of light that carry stories from the most extreme corners of the universe.<\/p>\n

As Coyle put it, \u201cThis event shows their detector works beautifully. There\u2019s so much more you can do with two detectors versus one. We are moving towards ultra-high-energy neutrino astronomy.\u201d<\/p>\n

And with that, a new era of cosmic discovery begins.<\/p>\n

The findings were reported in the journal Nature.<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"Credit: ZME Science\/SORA. In the dark silence three kilometers beneath the Mediterranean Sea, a scientific machine called KM3NeT…\n","protected":false},"author":2,"featured_media":61999,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3845],"tags":[27687,31960,7012,74,70,16,15],"class_list":{"0":"post-61998","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-physics","8":"tag-neutrino","9":"tag-neutrino-detectors","10":"tag-particle","11":"tag-physics","12":"tag-science","13":"tag-uk","14":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/114425015058541843","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/61998","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=61998"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/61998\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/61999"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=61998"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=61998"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=61998"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}