A Super-Energetic Neutrino That Reached Earth in 2023 Has Been Confirmed to Be Real. But Where Did It Come From?
In February 2023, a cosmic particle detector housed deep in the Mediterranean Sea recorded the arrival of a neutrino with approximately 20 to 30 times more energy than any other neutrino documented previously. Labelled KM3-230213A, the particle had a calculated energy of 220 petaelectronvolts (PeV), far greater than the 10 PeV of the previously most energetic neutrino. The finding generated a lot of excitement among physicists, but raised also many questions. Neutrinos are the most abundant par