Researchers have detected one of the most energetic particles ever to fall to Earth. Cosmic rays are high-energy particles that come from space sources like the Sun, but this recent discovery is more powerful than anything that can be explained by known sources in our galaxy or even beyond. The energy of the particle was 2.4 x 1020eV, which is millions of times the energy of the particles produced in the particle collider.
It was discovered in May 2021 using a facility called the Telescope Array, located near Salt Lake City in Utah. It has 500 surface detectors spread over 300 square miles of desert, designed to detect cosmic ray events. It has observed more than 30 ultra-high-energy cosmic rays since 2007, but this was the most powerful ray discovered so far.
It is the second most powerful cosmic ray ever discovered, beaten only by a ray discovered in 1991, which was named the Oh-My-God particle. The strange thing about these phenomena is that researchers don’t know where they are coming from.
“The particles have so much energy that they should not be affected by galactic and extra-galactic magnetic fields. You should be able to tell where in the sky they come from,” one of the researchers, John Matthews of the University of Utah, said in a statement. “But in the case of the oh-my-god particle and this new particle, you trace its trajectory to its source and there is not high enough energy to generate it. This is its mystery – what the heck is going on?”
Even a large event like a supernova would not be powerful enough to produce such particles, and this particle appears to come from an empty region of space at the edge of the galaxy called the Local Void. “These events seem as if they are coming from completely different places in the sky. It’s not like there’s some mysterious source,” said John Belz, another researcher. “It could be faults in the structure of space-time, colliding cosmic stars. I mean, I’m just spitting on these crazy ideas that people are coming up with because there’s no conventional explanation for it.
Researchers hope to use upcoming facilities such as expanding telescope arrays to further discover and study these events and learn about their possible source. “It’s a real mystery,” Belz said.
This research has been published in Science Journal.