Meet “Amaterasu”: Astronomers detect highest energy cosmic ray since 1991
Artist's illustration of extensive air showers induced by ultra-high-energy cosmic rays. Credit: Toshihiro Fujii/L-INSIGHT/Kyoto University Artist's illustration of extensive air showers induced by ultra-high-energy cosmic rays. Credit: Toshihiro Fujii/L-INSIGHT/Kyoto University
Astronomers involved with the Telescope Array experiment in Utah's West Desert have detected an ultra-high-energy cosmic ray (UHECR) with a whopping energy level of 244 EeV, according to a new paper published in the journal Science. It's the most energetic cosmic ray detected since 1991, when astronomers detected the so-called "Oh-My-God' particle, with energies of an even more impressive 320 EeV. Astronomers have dubbed this latest event the "Amaterasu" particle, after the Shinto sun goddess said to have created Japan. One might even call it the "Oh-My-Goddess" particle.
Cosmic rays are highly energetic subatomic particles traveling through space near the speed of light. Technically, a cosmic ray is just an atomic nucleus made up of a proton or a cluster of protons and neutrons. Most originate from the Sun, but others come from objects outside our solar system. When these rays strike the Earth's atmosphere, they break apart into showers of other particles (both positively and negatively charged).