The most energetic neutrino ever found has been picked up by a detector in the Mediterranean, but no one knows where it came from.
A neutrino is unlike any other subatomic particle known to science, as it is virtually weightless, highly volatile, and very rarely interacts with matter.
A million times smaller than an electron, the neutrino detected by the KM3NeT team has the same amount of energy as a ping pong ball.
That doesn’t sound like much, but relative to its size it is thousands of times more energy than can be produced by the Large Hadron Collider.
The next task for KM3NeT is to understand the neutrino’s cosmic origin.
It may be from a supermassive black hole or a supernova explosion – or even from a “dark accelerator”, a hypothetical object that the standard model of physics cannot describe.