Rare Ultra-High-Energy Particle Detected, Originating from Beyond the Milky Way

Rare Ultra-High-Energy Particle Detected, Originating from Beyond the Milky Way

Scientists Discover Subatomic Particle with Unprecedented Energy, Unlocking Cosmic Mysteries

In a groundbreaking discovery, space scientists have detected an ultra-high-energy particle that is believed to have traveled from beyond the Milky Way galaxy to Earth. This subatomic particle, invisible to the naked eye, possesses an energy equivalent to dropping a brick from waist height onto your toe. The findings, published in the journal Science, reveal that this particle rivals the energy of the famous “Oh-My-God” particle, the most energetic cosmic ray ever observed. The origins of these high-energy particles have long puzzled scientists, but this recent discovery brings us closer to unraveling the mysteries of the universe.

Tracking high-energy cosmic rays:

The recently discovered particle, affectionately named the Amaterasu particle after the sun goddess in Japanese mythology, was detected by the Telescope Array, a cosmic ray observatory located in Utah’s West Desert. Comprising 507 ping-pong table-sized surface detectors covering an area of 700 square kilometers, the Telescope Array has been operational since 2008. While it has observed over 30 ultra-high-energy cosmic rays, none have been as powerful as the Amaterasu particle, which struck the atmosphere above Utah on May 27, 2021. The secondary particles produced by this event were captured by the detectors, providing crucial data for analysis.

The energy of the Amaterasu particle was calculated to be approximately 244 exa-electron volts, whereas the “Oh-My-God” particle detected over three decades ago had an energy of 320 exa-electron volts. To put this into perspective, 1 exa-electron volt is equivalent to 1 billion gigaelectron volts, and 1 gigaelectron volt is 1 billion electron volts. This makes the Amaterasu particle an astonishing 244 quintillion electron volts. By comparison, the energy of an electron in the polar aurora is a mere 40,000 electron volts, highlighting the immense power of these cosmic rays.

See also  Former Scientists Find Fulfillment in Teaching, Inspiring the Next Generation

The mystery of their origins:

Despite decades of research, the exact sources of these ultra-high-energy particles remain elusive. Scientists believe they are connected to the most energetic phenomena in the universe, such as black holes, gamma-ray bursts, and active galactic nuclei. However, the largest particles discovered so far seem to originate from voids or empty spaces, devoid of any violent celestial events.

John Matthews, a research professor at the University of Utah and co-author of the study, explains that the two most energetic cosmic rays recorded, including the Amaterasu particle, do not appear to have any discernible source when their trajectories are traced back. Astronomers using visible telescopes have been unable to identify any significant and violent events that could produce such particles. The Amaterasu particle, in particular, seems to have originated from the Local Void, an empty region of space bordering the Milky Way galaxy.


The discovery of the Amaterasu particle and its unprecedented energy brings us closer to understanding the enigmatic origins of ultra-high-energy cosmic rays. While the source of these particles remains a mystery, scientists continue to explore the most energetic phenomena in the universe, hoping to unlock the secrets of our vast cosmos. The expansion of the Telescope Array, with the addition of 500 new detectors, promises to provide further insights into cosmic ray-induced particle showers, paving the way for new discoveries and a deeper understanding of our universe’s mysteries.