Artist’s illustration of the recently discovered “Amaterasu particle” ─ an extremely energetic cosmic ray detected by a surface detector array of the Telescope Array experiment.
In 1991, astrophysicists observed the highest-energy cosmic ray ever detected in our galaxy using the University of Utah Fly’s Eye experiment. Nicknamed the “Oh-My-God particle,” the cosmic ray’s energy surprised scientists as it was unprecedented and seemed impossible to originate within our galaxy. The Telescope Array experiment has since reported over 30 ultra-high-energy cosmic rays, including the second-highest extreme-energy cosmic ray observed on May 27, 2021. The “Amaterasu particle” that was observed carried an energy equivalent to dropping a brick from waist height, indicating the extreme nature of this event.
This latest discovery, led by the University of Utah in collaboration with the University of Tokyo, adds to the mystery of these ultra-high-energy cosmic rays that continue to baffle scientists. Despite advancements in research and observation techniques, the origin of these cosmic rays and their ability to reach Earth remains unknown. However, researchers believe that the Amaterasu particle might present a rare and unexplored phenomenon in the realm of particle physics.
The exploration of ultra-high-energy cosmic rays provides valuable insights into the nature of the universe, offering glimpses into the most extreme and powerful celestial events that occur beyond our galaxy. These cosmic rays are powerful, charged particles that travel through space, often reaching Earth and interacting with its atmosphere to create secondary showers of subatomic particles. Despite the challenges in tracing their exact trajectories and origins, the Telescope Array, with its array of surface detectors, offers scientists a glimpse into these remarkable phenomena.
Astrophysicists hope that the ongoing expansion of the Telescope Array will further enhance their ability to detect and study ultra-high-energy cosmic rays, unraveling the mysteries that surround these exceptional events. Published in the prestigious journal Science, this promising study provides a new path for understanding cosmic phenomena and could open the door to revolutionary breakthroughs in the field of astrophysics. For more information, please refer to www.science.org/doi/10.1126/science.abo5095.
