The discovery of the Amaterasu particle by the Telescope Array Project in Utah in 2021 has sparked new theories about the origins of ultrahigh-energy cosmic rays. Researchers suggest that these cosmic rays could be composed of ultraheavy atomic nuclei, which may explain their extreme energy levels, such as the Amaterasu particle's energy of approximately 240 x 10^18 electron volts. This study, involving an international team from institutions like Penn State and Kyoto University, posits that ultraheavy nuclei can travel through intergalactic space more efficiently than lighter particles, allowing them to maintain their high energy upon reaching Earth. The origins of these cosmic rays have puzzled scientists for over 60 years, with potential sources including catastrophic events like neutron star mergers and massive supernovae. The research also indicates that if ultraheavy nuclei are significant contributors to ultrahigh-energy cosmic rays, future observations may reveal a composition heavier than iron. The findings were published in the journal *Physical Review Letters* on May 7th, and the team aims to further investigate these cosmic phenomena using next-generation observatories.