Weird particle physics stories that blew our minds in 2023

The past year was a big win for particle physics, as experiments and nature conspired to produce some truly stunning results. Here are the biggest stories about the smallest particles from 2023. 

1. Here comes the sun goddess

An illustration showing a cosmic ray hitting the Telescope Array experiment’s detectors. (Image credit: Osaka Metropolitan University/L-INSIGHT, Kyoto University/Ryuunosuke Takeshige)

In 1992, astronomers were stunned to discover what they later named the Oh-My-God particle, a cosmic ray streaking into Earth’s atmosphere with a blistering 320 exa-electron-volts (EeV) of energy. On a human scale, that’s not a big number — roughly the energy of a dropped basketball hitting the ground. But for subatomic particles, it’s gigantic, far outpacing even our most powerful collider experiments. And this past year, the OMG particle got a partner: a 240 EeV particle dubbed Amaterasu, named after the goddess of the sun in Japanese mythology. Discovered with the Telescope Array Project in Utah, the new particle joins a rarefied list of ultra-relativistic high-energy cosmic rays. These rare particles come from the most energetic events in the universe but are ultimately mysterious. For example, Amaterasu appeared to come from the direction of the Local Void, a big batch of nothing in our cosmological neighborhood.