A High-Energy Cosmic Enigma: The Arrival of the Amaterasu Particle

by Mateo Gonzalez
Amaterasu Particle

Astronomers, using the Telescope Array experiment in Utah, have detected a cosmic particle named “Amaterasu,” exhibiting an extraordinary energy level of 244 EeV. This event parallels the detection of the famous “Oh-My-God” particle and has sparked curiosity regarding its origin and nature.

A mysterious, highly energetic particle from outer space, dubbed after a figure in Japanese mythology, has been identified.

An enigmatic high-energy particle from space has been observed impacting Earth, with its origins and precise nature still unclear. This scenario, seemingly ripped from the pages of a science fiction novel, is actually a scientific fact, confirmed by the research led by Associate Professor Toshihiro Fujii from Osaka Metropolitan University’s Graduate School of Science and Nambu Yoichiro Institute of Theoretical and Experimental Physics.

Depiction of the highly energetic cosmic ray captured by a surface detector array of the Telescope Array experiment, known as the “Amaterasu particle.” Attribution: Osaka Metropolitan University/L-INSIGHT, Kyoto University/Ryuunosuke Takeshige

Understanding Cosmic Phenomena

Cosmic rays are energetic, charged particles that originate from sources within and beyond our galaxy. Extremely high-energy cosmic rays are rare occurrences, with energy levels exceeding 1018 electron volts or one exa-electron volt (EeV), significantly surpassing the energy generated by the most advanced human-made accelerators.

Depiction of ultra-high-energy cosmic ray astronomy, contrasting highly energetic phenomena with weaker cosmic rays influenced by electromagnetic fields. Attribution: Osaka Metropolitan University/Kyoto University/Ryuunosuke Takeshige

The Telescope Array Project

Since 2008, Professor Fujii and an international scientific team have been engaged in the Telescope Array experiment. This cosmic ray detector comprises 507 scintillator surface stations and spans a vast 700 square kilometers in Utah, USA. On May 27, 2021, they recorded a particle with an astonishing energy level of 244 EeV.

A Cosmic Ray of Unprecedented Energy

Professor Fujii initially suspected an error upon discovering this ultra-high-energy cosmic ray, noting its energy level was unparalleled in the past thirty years.

This energy magnitude is on par with the highest ever recorded cosmic ray, the “Oh-My-God” particle, which was estimated at 320 EeV in 1991.

Visualization of the signal and event animation for the highly energetic “Amaterasu” particle. Attribution: Osaka Metropolitan University

Christening the Mysterious Particle

After considering several options, Professor Fujii and his team chose the name “Amaterasu” for the particle, inspired by the sun goddess from Shinto mythology, who is revered in the creation of Japan.

The Amaterasu particle’s origins and exact nature are as enigmatic as the deity it’s named after. Its discovery raises several unanswered questions and offers a potential avenue to explore the genesis of cosmic rays.

Continuing the Quest for Cosmic Origins

Professor Fujii noted that no corresponding astronomical object has been identified in the direction from which the cosmic ray came, suggesting the possibility of undiscovered astronomical phenomena or new physical principles beyond the Standard Model. He expressed a commitment to continue the Telescope Array experiment, with the upgraded TAx4 experiment and future observatories, to delve deeper into the origins of this extraordinarily energetic particle.

Source: “An extremely energetic cosmic ray observed by a surface detector array,” published on 23 November 2023 in Science.
DOI: 10.1126/science.abo5095

Frequently Asked Questions (FAQs) about Amaterasu Particle

What is the Amaterasu Particle?

The Amaterasu Particle is a high-energy cosmic ray detected using the Telescope Array experiment in Utah. It has an unprecedented energy level of 244 EeV and raises questions about its origin and composition.

How does the Amaterasu Particle compare to the “Oh-My-God” particle?

The Amaterasu Particle is comparable to the “Oh-My-God” particle, another high-energy cosmic ray, in terms of its energy level. The “Oh-My-God” particle, detected in 1991, had an estimated energy of 320 EeV.

What is the significance of the name “Amaterasu” for this particle?

The name “Amaterasu” is derived from the Japanese sun goddess and was chosen due to the particle’s mysterious nature and its potential to shed light on the origins of cosmic rays, much like the goddess in Japanese mythology.

What are the challenges in understanding the Amaterasu Particle?

Determining the origins and exact nature of the Amaterasu Particle is challenging. No corresponding astronomical objects have been identified, suggesting the possibility of new astronomical phenomena or physical principles beyond the Standard Model.

What is the Telescope Array experiment?

The Telescope Array experiment is a cosmic ray detector in Utah, USA, consisting of 507 scintillator surface stations over a 700 square kilometer area. It has been operational since 2008 and was instrumental in detecting the Amaterasu Particle.

More about Amaterasu Particle

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ScienceGeek101 November 23, 2023 - 8:55 pm

I’m a bit skeptical about the name ‘Amaterasu’. Feels like they’re trying too hard to make science sound mystical. or maybe it’s just me?

TechieTom November 23, 2023 - 10:28 pm

So they haven’t figured out where it came from? Seems like we still have a lot to learn about cosmic rays and the universe. Super interesting though.

AstroJenny November 24, 2023 - 1:34 am

Read about the Oh-My-God particle in college, never thought we’d see something similar again. This is groundbreaking, can’t wait to see what they discover next!

CosmicRayCatcher November 24, 2023 - 11:10 am

wow, this is incredible stuff! I mean, a particle with such high energy – really makes you think what’s out there in the universe.


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