![\"\"](\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2025\/06\/anita-internal1-sized.jpg\")
<\/a>ANITA flies over Antarctica to avoid signal interference and detect radio bursts from ice showers. Credit \u2013 Stephanie Wissel\/Penn State.<\/p>\nNeutrinos ruled out as source of anomaly<\/p>\n
Neutrinos are nearly massless, chargeless particles that rarely interact with matter. They constantly stream through space, Earth, and even the human body. <\/p>\n
Wissel explained<\/a> that \u201cyou have a billion neutrinos passing through your thumbnail at any moment,\u201d but detecting them is difficult precisely because they don\u2019t interact much. <\/p>\n When they do, however, they can offer crucial insights into events like supernovas or gamma-ray bursts.<\/p>\n This is what makes the ANITA signal<\/a> so confusing. If a neutrino caused it, the fact that it was detected at all would imply it traveled through the Earth without interacting until the very end. <\/p>\n Yet the steep angle and characteristics of the signal suggest otherwise. \u201cWe still don\u2019t actually have an explanation for what those anomalies are,\u201d Wissel said, but it\u2019s most likely not a neutrino.<\/p>\n Other detectors found no matching evidence<\/p>\n To test the findings, the team compared the ANITA data with information from two other major neutrino detectors<\/a>, IceCube in Antarctica and the Pierre Auger Observatory in Argentina. <\/p>\n Neither experiment recorded anything similar. This lack of supporting data, Wissel said, rules out the most likely known particle sources and adds weight to the idea that something new may be at play.<\/p>\n Extensive simulations and models were also used to eliminate background noise and known cosmic-ray signatures. <\/p>\n The process left researchers with only one conclusion that the signals remain \u201canomalous.\u201d<\/p>\n Next-gen detector may solve the mystery<\/p>\n Wissel and her colleagues at Penn State are already building a more advanced version of the ANITA experiment. The new detector, called PUEO, will offer greater sensitivity and a better chance at identifying what caused these unusual emissions. <\/p>\n She believes that PUEO may detect more of these signals and help researchers understand whether they\u2019re seeing signs of new physics or just rare environmental effects.<\/p>\n \u201cMy guess is that some interesting radio propagation effect occurs near ice<\/a> and also near the horizon that I don\u2019t fully understand,\u201d Wissel said. While the mystery remains unsolved, she\u2019s hopeful the next flight will bring answers.<\/p>\n