A rare and extremely high-energy particle has been detected falling to Earth by astronomers. Named after the Japanese sun goddess, Amaterasu, it is one of the highest-energy cosmic rays ever detected, according to scientists. The Amaterasu particle has an energy exceeding 240 exa-electron volts (EeV) and comes only second in recorded history to the Oh-My-God particle, another ultra-high-energy cosmic ray which was detected in 1991, possessing 320 EeV of energy. The origins of the particle are unknown, but experts believe that only the most powerful celestial events – bigger than a star explosion – can create them. Toshihiro Fujii, an associate professor at Osaka Metropolitan University in Japan, said he thought there "must have been a mistake" when he first discovered the particle. "It showed an energy level unprecedented in the last three decades," he said. The hope is now that the particle will pave the way for further investigations that could help shed light on ultra-high-energy cosmic rays and where they come from. Experts suggest it could indicate a much larger magnetic deflection than predicted, an unidentified source in the Local Void, or an incomplete understanding of high-energy particle physics. Another professor in Utah, John Beltz, said he is "spit-balling crazy ideas" to try to explain the mystery. "These events seem like they're coming from completely different places in the sky. It's not like there's one mysterious source," he said. "It could be defects in the structure of spacetime, colliding cosmic strings."