Astrophysicists using the Telescope Array experiment in Utah, the United States, have detected the second-highest extreme-energy cosmic ray. An artist’s illustration of the Amaterasu particle observed by a surface detector array of the Telescope Array experiment. Image credit: Osaka Metropolitan University / L-INSIGHT, Kyoto University / Ryuunosuke Takeshige. In 1991, the High Resolution Fly’s Eye experiment detected the highest-energy cosmic...
