Scientists Identify Extraterrestrial Origin of Enigmatic Cosmic Ray Detected in Utah

Join CNNs Wonder Theory science newsletter and discover the latest news on intriguing discoveries, scientific progress, and more. Delve into the universe and stay informed about space scientists' groundbreaking detection of an exceptionally rare, ultra-high-energy particle that may have journeyed to Earth from outside the Milky Way galaxy.

The newly published research in the journal Science reveals that the energy of this subatomic particle, though invisible to the naked eye, is comparable to the impact of dropping a brick on your toe from waist height. This finding challenges the previously observed "Oh-My-God" particle detected in 1991 as the most energetic cosmic ray ever observed. Cosmic rays, which are charged particles constantly raining down on Earth from space, can vary in energy levels. While lower-energy cosmic rays may come from the sun, the exceptionally high-energy ones are believed to originate from other galaxies and extragalactic sources.

Study coauthor John Matthews, a research professor at the University of Utah, explained that while one cosmic ray passes through the palm of your hand every second, these are low-energy rays. However, when it comes to high-energy cosmic rays, it's more like one per square kilometer per century, so they are unlikely to pass through your hand.

One of the cosmic ray detectors that make up the Telescope Array, which is based in Utah.

University of Utah, courtesy of them, states that the exact origins of these high-energy particles remain unclear despite years of research. While it is believed that they are connected to the most energetic phenomena in the universe, such as black holes, gamma-ray bursts, and active galactic nuclei, the largest particles discovered so far seem to come from voids or empty space where no violent celestial events have occurred.

The high-energy cosmic rays are being tracked by the Telescope Array, a cosmic ray observatory located in Utah's West Desert. A newly discovered particle, which has been nicknamed the "Amaterasu particle" after the sun goddess in Japanese mythology, was recently detected by this observatory.

The Telescope Array, launched in 2008, consists of 507 surface detectors the size of ping-pong tables spanning 700 square kilometers (270 square miles). It has recorded over 30 ultra-high-energy cosmic rays, including the Amaterasu particle, the largest one yet, which entered Earth's atmosphere above Utah on May 27, 2021. The secondary particles it produced upon impact were captured by the detectors, providing valuable data. According to the study, the number of particles detected by each detector indicates the energy level of the primary cosmic ray.

The event set off 23 surface detectors, registering a calculated energy of approximately 244 exa-electron volts. The "Oh My God particle" discovered over 30 years ago measured 320 exa-electron volts.

To put this in perspective, 1 exa-electron volt is equivalent to 1 billion gigaelectron volts, and 1 gigaelectron volt equals 1 billion electron volts. Therefore, the Amaterasu particle's energy is 244,000,000,000,000,000,000 electron volts. In contrast, the typical energy of an electron in the polar aurora is 40,000 electron volts, as reported by NASA.

A telescope station in Utah, with stars swirling overhead.

From the University of Utah

According to Glennys Farrar, a physics professor at New York University, an ultra-high-energy cosmic ray contains tens of millions of times more energy than any particle accelerator created by humans, including the Large Hadron Collider, the most powerful accelerator in existence.

Farrar, not involved in the study, explained via email that a region of extremely high magnetic fields, like a naturally occurring super-sized LHC, is needed. However, the required conditions are very rare, making the sources rare as well. The particles are dispersed into the vast universe, making the chances of one hitting Earth very slim.

While the atmosphere generally protects humans from any harmful effects of these particles, cosmic rays can sometimes cause computer malfunctions. These particles, as well as space radiation in general, pose a greater risk to astronauts, with the potential to cause damage to DNA and numerous cellular processes, according to NASA.

Mysterious source

The source of these ultra-high-energy particles baffles scientists.

Matthews, a co-spokesman for the Telescope Array Collaboration, commented that the trajectories of the two largest recorded cosmic rays seemed "quite random," and when traced back, there is no apparent source of sufficient high-energy to produce such particles. Specifically, the Amaterasu particle appeared to have originated from the area known as the Local Void, an empty region of space bordering the Milky Way galaxy.

The infrared and visible-light data from NASA's James Webb Space Telescope and Hubble Space Telescope were combined to create a panchromatic view of galaxy cluster MACS0416. In this image, the shortest wavelengths were color-coded blue, the longest red, and intermediate green, revealing a vivid landscape of galaxies spanning from 0.4 to 5 microns. This colorful view is considered one of the most vibrant views of the universe ever created.

The newly captured image of the Cosmic Christmas tree by the Hubble and Webb telescopes is truly dazzling. According to Matthews, even the two highest-energy events, including the recent discovery of the Oh-My-God particle, do not seem to indicate anything significant. Visible telescopes used by astronomers have not revealed anything large or violent in the vicinity.

"It originates from a region that appears as a vacuum, a local empty space. What is happening there?" The expansion of the Telescope Array could offer some explanations. Once finished, 500 new detectors will enable the Telescope Array to record cosmic ray-induced particle showers across an area of 2,900 square kilometers (about 1,120 square miles), nearly the size of Rhode Island, as per the University of Utah statement.