KM3NeT experiment detects highest-energy cosmic neutrino ever recorded

The field of neutrino astronomy is expanding through global efforts, including the IceCube Neutrino Observatory in Antarctica and the KM3NeT experiment located in the Mediterranean Sea. While the Nobel Prize in Physics recently recognized Francis Halzen for his contributions to IceCube, the KM3NeT project is making significant strides of its own.

In February 2025, KM3NeT was featured on the cover of the journal Nature after detecting KM3-230213A, the highest-energy cosmic neutrino ever recorded. This particle was 30 times more energetic than any previously observed neutrino. The detection provides the first evidence that such high-energy neutrinos are produced in the universe, offering insights into violent cosmic events occurring outside our galaxy.

Researchers, including those from the National Centre for Scientific Research Demokritos, note that neutrinos act as unique messengers. Unlike photons or charged particles, neutrinos are not deflected by interstellar magnetic fields and are not easily absorbed, providing a new tool for understanding the origin and nature of cosmic rays and astrophysical phenomena.