Astronomers close in on the source of the highest energy particles | by Ethan Siegel | Starts With A Bang! | Jun, 2025

On Earth, our particle accelerators can reach tera-electron-volt (TeV) energies. Particles from space are thousands of times as energetic.

Here on Earth, if you want to observe particles at the highest possible energies, you have two potential approaches you can choose from. You can isolate charged particles in a laboratory and accelerate them with a combination of electric and magnetic fields, either linearly or in a circular path, to higher and higher energies before either releasing them in a particular direction or smashing them into other particles. These particle physics experiments have created enormous numbers of high-energy particles and given us enormous amounts of data that’s useful for studying nature, allowing us to understand the building blocks of reality at a fundamental level. We’ve accelerated particles up to GeV and even TeV energies in the lab: to billions (10⁹) or even trillions (10¹²) of electron-volts.

But nature, even in the depths of space, has ways to far surpass anything humans can achieve on Earth. Natural particle accelerators — in the form of star-forming regions, black holes, supernovae, and even pulsing neutron stars — frequently reach energies much greater than even those found at…