In a cosmic mystery that has left scientists astounded, Earth recently experienced a powerful encounter with an "ultra-high-energy" cosmic ray named "Amaterasu," marking one of the most energetic cosmic events since the famous "Oh My God" particle in 1991. Researchers are grappling with the enigma of its origin and the cosmic void from which it emerged. Cosmic rays, comprising highly energetic particles like protons or helium nuclei, constantly permeate the universe. However, a subset of these particles, known as "ultra-high-energy cosmic rays," possesses energy levels exceeding one exa-electron volt (1 quintillion electron volts), a million times more energetic than particles from human-made accelerators. Detected on May 21, 2021, by the Telescope Array project in Utah, "Amaterasu" boasted a staggering 244 exa-electron volts of energy, rivaling the record-breaking "Oh My God" particle. Osaka Metropolitan University (OMU) researchers detailed their findings, describing the particle in a study set to be published in the journal Science on Nov. 24. They named it after the Shinto sun goddess Amaterasu, who, according to belief, played a role in Japan's creation. Lead author Toshihiro Fujii expressed his initial disbelief at the unprecedented energy levels, stating, "I thought there must have been a mistake." The mystery deepens as the cosmic ray's origin points to a cosmic void devoid of known galaxies, nebulas, or other structures. While possibilities include deflection by magnetic fields or sources such as supernovae, black hole mergers, and pulsars, the researchers remain uncertain. The "unknown astronomical phenomena and novel physical origins beyond the Standard Model [of physics]" are considered potential explanations, challenging current understanding.