A neutrino slammed into Earth in 2023 with so much energy that it looked almost unreal. The particle carried about 220 peta–electron volts, or PeV, making it the most energetic neutrino ever reported. That is roughly 100,000 times more energy than the highest-energy particle produced by the Large Hadron Collider. Now physicists at University of Massachusetts Amherst say the event may fit a bold explanation. In a study published in Physical Review Letters, they argue the neutrino could have come from a tiny, ancient black hole that reached the end of its life and detonated. The team includes Andrea Thamm, Joaquim Iguaz Juan and Michael Baker. The detection came from the KM3NeT Collaboration, a neutrino experiment in the Mediterranean Sea. It recorded the event called KM3-230213A. The puzzle deepened because IceCube Neutrino Observatory, a larger and longer-running detector, did not see anything like it. A record neutrino and an awkward mismatch When two major detectors tell different stories, you have to ask why. IceCube has observed high-energy neutrinos for years. It has measured events in …