The Astro Journals

12/03/2023

Exploring the feasibility of sending humans to Europa, Jupiter's icy moon, presents formidable challenges, according to experts. Dr. Alyssa Rhoden, Principal Scientist at the Southwest Research Institute, and Dr. Francis Nimmo, Professor in Earth & Planetary Sciences at UC Santa Cruz, underscore the formidable obstacle of Europa's harsh radiation environment. Despite the allure of Europa's vast liquid ocean potentially hosting life, the intense radiation from Jupiter's magnetic field raises serious doubts about the viability of human missions on its surface.

While Europa harbors a vast liquid ocean that could potentially host life, the intense radiation from Jupiter's magnetic field makes human missions precarious. Even radiation-hardened spacecraft require robust shielding, prompting doubts about human survival on Europa's surface.

NASA's upcoming Europa Clipper spacecraft, scheduled for launch in 2024, will orbit Jupiter rather than Europa to shield its electronics from Jupiter's radiation belts. The prospect of human exploration in orbit around Europa, while offering some advantages, still presents formidable logistical challenges. Dr. Rhoden suggests an orbiting colony could support short-term research excursions, but resupplying essentials like food and water, potentially unattainable from Europa, poses significant hurdles. The extended travel time from Earth to Europa and the vulnerability of surface equipment to external attacks further complicate the feasibility of human missions.

While acknowledging the allure of sending humans to Europa, experts caution that the concept remains distant from practicality compared to missions involving orbiting spacecraft, landers/rovers, or autonomous drills. The complexities of sustaining human life in Europa's hostile environment, coupled with the extended resupply timelines, raise questions about the viability and benefits of such ventures. Ultimately, the potential for human exploration on Europa remains speculative, awaiting advancements in technology and a more thorough understanding of the challenges posed by this distant moon.

12/02/2023

The Artemis 3 mission, which is now tentatively scheduled to fly in December 2025, may have to wait until at least 2027.

NASA's endeavor to return humans to the moon for the first time since the Apollo program with the Artemis 3 mission will likely be delayed because it is jeopardized by "multiple challenges" and an ambitious schedule, the U.S. Government Accountability Office announced Thursday (Nov. 30).

Based on interviews with NASA and industry officials and reviewing documentation, the GAO reported it found a significant amount of pending technical work on the human landing system or HLS, a variant of SpaceX's Starship and NASA's mode of transport to the moon's surface. Also remaining is crucial design work to incorporate larger oxygen tanks into the space suits that would be used by astronauts on the moon, the report stated.

The HLS will use up its propellant reservoir just getting into orbit, so it will need to be refueled before heading to the moon. As per the current plan, a multi-step effort would see a Starship fuel depot placed in orbit first, followed by multiple tankers to transfer methane and liquid oxygen into that depot so that it is fully refueled before going to the moon.

Headquartered at the Marshall Space Flight Center in Alabama, the HLS program is still officially working toward a December 2025 launch, and aiming to complete its development in a total of 79 months — about a year sooner than the average for major NASA projects, most of which don't involve human spaceflight. But GAO says that timeline is unlikely since complex technical work remains, including figuring out how to transfer propellant in orbit for which "SpaceX has made limited progress in maturing those technologies."

The HLS program and SpaceX have delayed eight out of 13 key milestones by six months to a year, causing two of the postponed milestones to now take place in 2025, the same year as the currently scheduled Artemis 3 launch. If the HLS lander development takes on average as much time as other major projects at NASA, the Artemis 3 mission would occur in early 2027, the report stated.

For that launch timeline to be met though, a second pressing concern related to a design change in space suits being developed by Axiom Space must be resolved. Earlier this year, the company unveiled a prototype of the suit, which it would rent to NASA for the Artemis moon landing missions. So far, Axiom has completed two milestones in work related to developing the space suits but they are still in the early development phases, the latest GAO report said.

Much of the pending work appears to be related to the suit design. NASA requires Axiom to develop a suit that can provide 60 minutes of emergency life support, but "NASA's original design did not provide the minimum amount of emergency life support needed for the Artemis 3 mission," according to the report.

So Axiom now plans to rearrange components of the space suit such that it can accommodate larger oxygen tanks but if that's not possible, it will need to alter the current design which would take more time.

If NASA officially delays the launch date for Artemis 3 to 2027, it would end up being one year sooner than its original goal of 2028. The Trump administration in 2019 had set a timeline of 2024, which NASA eventually pushed out to the current launch estimate in December 2025.

But even NASA found that 2025 date to be optimistic; in June 2023, agency leadership pointed out that delays with HLS/Starship development made it unlikely that Artemis 3 would be able to meet that timeline.

12/01/2023

Astronomers have recently identified a novel phenomenon termed "SpaceX auroras," resulting from de-orbiting SpaceX rocket boosters creating temporary holes in the ionosphere, the atmospheric layer situated 50 to 400 miles above Earth's surface. These ionospheric holes manifest as glowing red orbs, distinct from traditional auroras, and are attributed to secondary boosters falling back to Earth after detaching from the rockets. Researchers at the McDonald Observatory in Texas have observed these unique red lights, occurring post-SpaceX Falcon 9 launches, with an increasing frequency of 2 to 5 sightings each month.

While these SpaceX auroras do not pose a threat to the environment or life on Earth, concerns have been raised about potential repercussions for astronomical observations and communication systems. Ionospheric holes, induced by ascending rockets and de-orbiting boosters, temporarily disturb the ionized gas in the atmosphere, leading to red light emissions akin to traditional auroras. Although the holes close within 10 to 20 minutes, their cumulative impact on astronomical science is under evaluation.

The de-orbiting boosters release fuel during controlled burns to navigate debris safely into the southern Atlantic Ocean, generating smaller and more circular ionospheric holes. These holes appear approximately 90 minutes post-launch at an altitude of about 185 miles. While not as enduring as those created during rocket launches, the frequency of these smaller holes is on the rise. Researchers are closely monitoring their influence on astronomy and assessing potential disruptions to shortwave radio communication and GPS signals.

Beyond their implications, studying these ionospheric holes could enhance our understanding of this atmospheric layer. SpaceX's rocket boosters also contribute to other captivating light displays, such as "SpaceX spirals," resulting from the release of leftover fuel in space, forming illuminated clouds of ice crystals. With the escalating number of SpaceX launches, the occurrence of these auroras and spirals is anticipated to become more commonplace in the future.

11/30/2023

NASA has announced the imminent launch of a groundbreaking Antarctic Long Duration Balloon (LDB) Campaign, featuring a trio of scientific balloon flights set to embark on record-breaking missions. The campaign, slated to commence at the beginning of December, will leverage stadium-sized zero-pressure balloons to support a total of five scientific endeavors.

Zero-pressure balloons, equipped with open ducts for controlled gas release, expand as they accumulate heat from the Sun during ascent. This innovative technology allows for extended flight durations, particularly viable during the polar summer when continuous sunlight is available. Despite the inherent limitations in flight duration due to heat loss after sunset, NASA's Balloon Program Office is optimistic about the unique opportunities provided by the polar summer environment.

The primary mission of the 2023 launch is the Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory (GUSTO). GUSTO aims to break the previous long-duration balloon flight record of just over 55 days. The scientific payload will conduct measurements of emissions from the interstellar medium, the cosmic material located between stars. The data collected during the flight over Antarctica will unravel the intricacies of the interstellar medium, shedding light on the life cycle of interstellar gas, star formation, destruction, and gas flow near the center of our Milky Way galaxy.

GUSTO's telescope, capable of detecting oxygen, carbon, and nitrogen emission lines, will provide valuable spectral and spatial resolution information. This will aid researchers in mapping extensive sections of the Milky Way galaxy and the nearby Large Magellanic Cloud.

While GUSTO takes the spotlight, the Antarctic LDB campaign will also feature the Anti-Electron Sub-Orbital Payload (AESOP-Lite) mission, focused on studying cosmic ray electrons and positrons. Furthermore, the Long durAtion evalUation solaR hand LAunch (LAURA) mission will utilize solar panels to extend the hand launch platform's duration, addressing challenges associated with hand-launched balloon flight time.

December will witness hand-launched missions, including NASA's Anihala (Antarctic Infrasound Hand Launch) mission. Anihala, a component of the AESOP-Lite payload, will measure background sound subtleties in Earth's stratosphere, offering a unique opportunity to observe these phenomena in a region minimally impacted by human civilization.

Andrew Hamilton, acting chief of NASA's Balloon Program Office, emphasized that the stratospheric wind conditions over Antarctica during this annual launch present a unique and valuable opportunity for sustained near-space missions, lasting days or weeks. This ambitious endeavor underscores NASA's commitment to advancing scientific exploration and understanding of our universe.

11/30/2023

NASA’s Dragonfly mission has been authorized to proceed with work on final mission design and fabrication – known as Phase C – during fiscal year (FY) 2024. The agency is postponing formal confirmation of the mission (including its total cost and schedule) until mid-2024, following the release of the FY 2025 President’s Budget Request.

Earlier this year, Dragonfly – a mission to send a rotorcraft to explore Saturn’s moon Titan – passed all the success criteria of its Preliminary Design Review. The Dragonfly team conducted a re-plan of the mission based on expected funding available in FY 2024 and estimate a revised launch readiness date of July 2028. The Agency will officially assess the mission’s launch readiness date in mid-2024 at the Agency Program Management Council.

“The Dragonfly team has successfully overcome a number of technical and programmatic challenges in this daring endeavor to gather new science on Titan,” said Nicola Fox, associate administrator of NASA’s Science Mission Directorate at NASA headquarters in Washington. “I am proud of this team and their ability to keep all aspects of the mission moving toward confirmation.”

Dragonfly takes a novel approach to planetary exploration, for the first time employing a rotorcraft-lander to travel between and sample diverse sites on Titan. Dragonfly’s goal is to characterize the habitability of the moon’s environment, investigate the progression of prebiotic chemistry in an environment where carbon-rich material and liquid water may have mixed for an extended period, and even search for chemical indications of whether water-based or hydrocarbon-based life once existed on Titan.

Dragonfly is being designed and built under the direction of the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, which manages the mission for NASA. The team includes key partners at NASA’s Goddard Space Flight Center in Greenbelt, Maryland; Lockheed Martin Space in Littleton, Colorado; Sikorsky, a Lockheed Martin company; NASA’s Ames Research Center in Silicon Valley, California; NASA’s Langley Research Center in Hampton, Virginia; Penn State University in State College, Pennsylvania; Malin Space Science Systems in San Diego, California; Honeybee Robotics in Pasadena, California; NASA’s Jet Propulsion Laboratory in Southern California; CNES (Centre National d’Etudes Spatiales), the French space agency, in Paris, France; DLR (German Aerospace Center) in Cologne, Germany; and JAXA (Japan Aerospace Exploration Agency) in Tokyo, Japan. Dragonfly is the fourth mission in NASA’s New Frontiers Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the Science Mission Directorate.

11/29/2023

The ‘Message in a Bottle’ initiative will see people’s names engraved on the Europa Clipper spacecraft, with members of the public urged to submit their names for free before the end of 2023.

The mission is set to launch in October 2024, reaching Jupiter orbit 2.9 kilometres (1.8 billion miles) away in 2030. It will aim to investigate whether the ocean beneath the icy crust of Europa can harbour life.

11/28/2023

11/28/2023

If a rogue star were to come within 100 astronomical units (AU) of our Sun, it could potentially disrupt the delicate gravitational balance of our Solar System. While the probability of such an event is low, the consequences could be significant. Research, detailed in the paper "Future Trajectories of the Solar System: Dynamical Simulations of Stellar Encounters Within 100 au," explores the outcomes of such encounters, shedding light on the fate of our planetary system.

The study, led by astronomer Sean Raymond from the Laboratoire d'Astrophysique de Bordeaux, considered scenarios where a rogue star, also known as an intergalactic or hypervelocity star, closely approaches our Sun. These stars, propelled out of their original galaxies, travel through interstellar space, and while most never come close to another solar system, the possibility is not entirely negligible.

The simulations involved running 12,000 scenarios, introducing a single rogue star to the Solar System's eight planets. The rogue stars in the simulations matched the masses and velocities of stars in our stellar neighborhood. Surprisingly, the results indicate that there's a greater than 95 percent chance that all eight planets would survive such an encounter, although their orbital configurations might be markedly altered.

For Earth specifically, potential outcomes range from colliding with another planet (0.48 percent chance) to being ejected to the Oort Cloud, a distant region housing icy bodies on the fringes of the Solar System. There's also a rare but catastrophic possibility of Earth being captured by the passing star, leading to the annihilation of the Solar System, with only Jupiter remaining in orbit.

The long-term habitability of Earth in such scenarios hinges on the specific changes to its orbit. While surviving planets would likely remain gravitationally bound to the Sun, their orbits could be dramatically disrupted, potentially pushing some into the distant Oort Cloud. This raises questions about the continued habitability of Earth, with potential outcomes ranging from becoming a rogue planet to maintaining habitable conditions in a new orbital configuration.

Despite the infinitesimally small odds of a stellar flyby within 100 AU, these simulations provide valuable insights into the dynamical stability of our Solar System and the potential consequences of interactions with wandering stars in the vast cosmic expanse.

11/28/2023

For the first time in history, two planets have been home to testing future aircraft designs. In this world, a new rotor that could be used with next-generation Mars helicopters was recently tested at NASA's Jet Propulsion Laboratory in Southern California, spinning at near-supersonic speeds (0.95 Mach). Meanwhile, the agency's Ingenuity Mars Helicopter has achieved new altitude and airspeed records on the Red Planet in the name of experimental flight testing.

"Our next-generation Mars helicopter testing has literally had the best of both worlds," said Teddy Tzanetos, Ingenuity's project manager and manager for the Mars Sample Recovery Helicopters. "Here on Earth, you have all the instrumentation and hands-on immediacy you could hope for while testing new aircraft components. On Mars, you have the real off-world conditions you could never truly re-create here on Earth." That includes a whisper-thin atmosphere and significantly less gravity than on Earth.

The next-generation carbon fiber rotor blades being tested on Earth are almost 4 inches (more than 10 centimeters) longer than Ingenuity's, with greater strength and a different design. NASA thinks these blades could enable bigger, more capable Mars helicopters. The challenge is that as the blade tips approach supersonic speeds, vibration-causing turbulence can quickly get out of hand.

To find a space big enough to create a Martian atmosphere on Earth, engineers looked to JPL's 25-foot wide, 85-foot-tall (8-meter-by-26-meter) space simulator—a place where Surveyor, Voyager, and Cassini got their first taste of space-like environments. For three weeks in September, a team monitored sensors, meters, and cameras as the blades endured run after run at ever-higher speeds and greater pitch angles.

"We spun our blades up to 3,500 rpm, which is 750 revolutions per minute faster than the Ingenuity blades have gone," said Tyler Del Sesto, Sample Recovery Helicopter deputy test conductor at JPL. "These more efficient blades are now more than a hypothetical exercise. They are ready to fly."

At around the same time, and about 100 million miles (161 million kilometers) away, Ingenuity was being commanded to try things the Mars Helicopter team never imagined they would get to do.

Ingenuity was originally slated to fly no more than five times. With its first flight entering the mission logbook more than two-and-a-half years ago, the helicopter has exceeded its planned 30-day mission by 32 times and has flown 66 times. Every time Ingenuity goes airborne, it covers new ground, offering a perspective no previous planetary mission could achieve. But lately, Team Ingenuity has been taking their solar-powered rotorcraft out for a spin like never before.

"Over the past nine months, we have doubled our max airspeed and altitude, increased our rate of vertical and horizontal acceleration, and even learned to land slower," said Travis Brown, Ingenuity's chief engineer at JPL. "The envelope expansion provides invaluable data that can be used by mission designers for future Mars helicopters."

Limited by available energy and motor-temperature considerations, Ingenuity flights usually last around two to three minutes. Although the helicopter can cover more ground in a single flight by flying faster, flying too fast can confuse the onboard navigation system. The system uses a camera that recognizes rocks and other surface features as they move through its field of view. If those features whiz by too fast, the system can lose its way.

So, to achieve a higher maximum ground speed, the team sends commands for Ingenuity to fly at higher altitudes (instructions are sent to the helicopter before each flight), which keeps features in view longer. Flight 61 established a new altitude record of 78.7 feet (24 meters) as it checked out Martian wind patterns. With Flight 62, Ingenuity set a speed record of 22.3 mph (10 meters per second)—and scouted a location for the Perseverance rover's science team.
The team has also been experimenting with Ingenuity's landing speed. The helicopter was designed to contact the surface at a relatively brisk 2.2 mph (1 mps) so its onboard sensors could easily confirm touchdown and shut down the rotors before it could bounce back into the air.

A helicopter that lands more slowly could be designed with lighter landing gear. So, on Flights 57, 58, and 59 they gave it a whirl, demonstrating that Ingenuity could land at speeds 25% slower than those at which it was originally designed to land.

All this Martian Chuck Yeager-ing is not over. In December, after solar conjunction, Ingenuity is expected to perform two high-speed flights, during which it will execute a special set of pitch-and-roll angles designed to measure its performance.

11/26/2023

The temperature of the universe is surprisingly varied, with some places far from any star being a lot hotter than you might expect, but what about the other end of the scale? Absolute zero (0 K, -273.16°C, or -459.68°F) represents a theoretical limit on how cold things can get, but what is the practical limit? How cold, then, is the coldest place in the universe?

If you want to be really pedantic there's a very high chance that the true coldest place in the universe is inside of some alien species' research lab, assuming someone in the universe has exceeded our technology for creating the very cold. Finding that, however, will presumably have to wait for a fair while after we make contact, since “What are the coldest conditions you have produced?” is probably not the optimum opening topic of conversation.

In terms of places humanity is aware of, we certainly haven't seen anything natural that is as cold as what we have produced ourselves. Laser cooling followed by expansion has been used to remove so much heat from clusters of atoms that they are 0.000000000038 above absolute zero. Someone will probably continue to put more zeros between the decimal point and the first numeral, because there is a lot of important research that requires colder and colder temperatures. Still, it's hard for most people to get to excited about dropping another trillionth of a degree.

Moreover, for most people a cloud of a few hundred exotic atoms doesn't really count as a place. If you're looking for something a little roomier, however, humans still probably have nature beat. If you want to study the behavior of substances such as liquid helium in substantial quantities you need to cool not just them, but their surrounding environment to temperatures a few degrees above absolute zero, and for some studies it helps to keep pushing things lower.

Ok, but say you consider that cheating. You want to know the coldest natural location. The aftermath of the Big Bang saw a superheated universe, but as it expanded it cooled, like a gas in a refrigeration cycle. The energy left over from the original explosion provides the cosmic background radiation, which, generally speaking puts a 2.7 K (-455°F) floor under temperatures everywhere. As the universe ages, this temperature will fall further, but it does so very, very slowly.

So is that the answer? Anywhere without another heat source sits at 2.7 K, making the coldest place in the universe a draw between an infinite number of places? Not that long ago we thought so, but in 1995 astronomers found something unexpected deep in the southern skies.

The Boomerang Nebula (named before we had a good image of its ghost-like shape) has a temperature of just 1 K (-458°F), causing it to absorb energy from the cosmic background around it, rather than emit it as a star's neighborhood normally would.

This temperature has been confirmed in multiple studies, but it took 20 years to find an explanation. After all, the Boomerang is a planetary nebula, or on the way to becoming one. The name is misleading, planetary nebulae are formed when red giant stars not massive enough to explode as a supernova turn into white dwarfs instead.

The Boomerang is thought to be so cold because it is expanding ridiculously fast, but whatever is driving that expansion is not supplying much heat. A 2017 paper found evidence for the presence of an interloper star besides the one that produced the nebula in the first place. The gravitational interaction between the two is thought to be supercharging the expansion of the nebula's gases. There may be some extra complexity to the story, but so far no one seems to have refuted the central idea.

Presumably the Boomerang, a relatively modest 5,000 light-years from Earth, is not the only planetary nebula where such events are taking place. In such a large universe, there's probably a nebula driven by the same processes that is even colder. However, the Boomerang is only a few thousand years old and is already starting to warm up, so such anomalies don't last long in cosmic terms.

There's also another twist to the tale. If temperature is defined as the random movement of the particles that make something up, negative temperatures should be impossible. Yet, in 1949, the existence of temperatures below absolute zero was predicted.

Physicists define temperature in more than one way, including that temperature is a measure of the order within a system, with more order equating to lower temperatures. By this definition negative temperatures do exist, potentially including within the atmospheres of gas giant planets.

Certainly, if we accept these definitions, anywhere with negative temperatures outranks somewhere a degree above absolute zero. However, it's doubtful many people would think this counts, so it looks like the Boomerang Nebula it is.

11/26/2023

The so-called giant radio galaxies (GRGs) are radio galaxies with an overall projected linear length exceeding at least 2.3 million light years. They are rare objects grown in low-density environments. In general, GRGs are important for astronomers to study the formation and the evolution of radio sources.

Many GRGs are double-lobed radio galaxies that have become known as double radio sources associated with active galactic nuclei (AGN), or DRAGNs. They can be difficult to identify in radio surveys as lobes of radio galaxies may be detected as multiple sources. Therefore, many detectable GRGs may remain unidentified. FIRST, utilizing the Very Large Array (VLA), due to its low frequency and good sensitivity to extended sources, has the potential to unveil the presence of many new GRGs.

That is why a team of astronomers led by University of Wisconsin-Madison's Soren Ramdhanie decided to analyze FIRST in order to search for previously undetected GRGs. They employed the DRAGNhunter algorithm to identify double-lobed radio galaxies in the FIRST data and investigated the newfound sources.

"DRAGNhunter identifies DRAGNs by pairing cataloged extended radio sources based on their separation and relative alignment, then uses the likelihood ratio approach to search for the probable host galaxy in the AllWISE catalog," the researchers explained.

As a result, Ramdhanie's team has initially identified 80 giant radio galaxies in the FIRST dataset using the DRAGNhuster algorithm. It turns out that 17 of the detected GRGs are within 5 arcseconds of known galaxies of this type and are not new discoveries.

The newfound GRGs were found at redshifts between 0.51 and 1.32. Only six galaxies of the sample have spectroscopic redshifts, while the remaining 57 have estimated photometric redshifts. The GRG with the highest redshift is designated DELS J225125.27−025451.8.

The largest GRG reported in the study received designation DELS J093016.68+114241.4. It has a projected linear size of nearly 4 million light years and was found at a redshift of 1.14. The smallest one, DELS J234027.85+003057.4 at a redshift of 1.01, has a projected linear size of 2.3 million light years.

The study also found that the new GRGs have 1.4 GHz luminosities ranging from 25.34 to 27.09 W/Hz. The flux density of these galaxies is dispersed and it was measured to be between 7.14 and 337.85 mJy.

Further studies of the newfound GRGs are required in order to shed more light on their properties. The astronomers added that some of these GRGs may have been identified as extended radio galaxies in previous catalogs.

11/25/2023

Over the years, scientists have managed to unveil the existence of quite a few intriguing particles, pushing the entire field of physics forward with each discovery. There's the "God Particle" for instance, aka the Higgs Boson that grants all other particles their masses. There's also the so-called "Oh My God!" particle, an unimaginably energetic cosmic ray.

But now we have a new particle in town. It's named the "sun goddess" particle — and is fittingly extraordinary.

This particle has an energy level one million times greater than what can be generated in even humanity’s most powerful particle accelerators; it appears to have fallen to Earth in a shower of other, less energetic particles. Like the "Oh My God!" particle, these bits come from faraway regions of space and are known as cosmic rays. The particle has been dubbed "Amaterasu" after Amaterasu Ōmikami, the goddess of the sun and the universe in Japanese mythology, whose name means "shining in heaven." And just as its mythological namesake is shrouded in mystery, so too is the Amaterasu particle. Its discoverers, including Osaka Metropolitan University researcher Toshihiro Fujii, don’t know where the particle came from or indeed what it is. They also still aren't sure what kind of violent and powerful process could have given rise to something as energetic as Amaterasu.

The hope is that, just as Amaterasu is credited with the creation of Japan according to the Shinto tradition, the Amaterasu particle can help create an entirely new branch of high-energy astrophysics.

High-energy cosmic rays are extremely rare to begin with, but Fujii said the Amaterasu particle has an energy level not seen in a staggering 30 years of cosmic ray detections.

In fact, when the researchers spotted Amaterasu with the Telescope Array experiment — involving 507 detectors spread across 270 square miles (699 square kilometers) of the high desert of Millard County, Utah —they initially thought the detection must be some kind of mistake.

"I thought it would be my mistake or bug, and then after checking the details of the event, I was excited to find it was not an error," Fujii said.

First spotted by the Telescope Array experiment on May 27, 2021, the Amaterasu particle exhibits an energy of 224 exa-electron volts (EeV). For contest, one EeV is equivalent to 10¹⁸ electron volts. This puts Amaterasu on a similar energy level to the most energetic cosmic ray ever discovered — yes, that's the "Oh My God!" particle, which was detected in Oct. 1991 by the Fly’s Eye camera in Dugway Proving Ground, Utah. The latter had an energy of 320 EeV.

"The Amaterasu particle should be an important messenger from the universe about extremely energetic phenomena, but we need to disentangle the origin of this mysterious particle," Fujii explained.

There isn’t an astrophysical object, or any cosmic event for that matter, in the direction from which the sun goddess particle appears to have come from. That's why scientists are pretty unclear on what led to its creation. But, while the origins of the Amaterasu particle may be currently unknown, Fujii does have some avenues of investigation to follow up on. Importantly, some of these ideas could extend beyond the Standard Model of particle physics, which is the best outline we have of the universe’s particle zoo and how each of those particles interact with one another.

"One possibility is the particle has been accelerated by extremely energetic phenomena, such as a gamma-ray burst or a jet from a feeding supermassive black hole at the center of active galactic nuclei," Fujii said. "Another possibility is creation in an exotic scenario such as the decay of super heavy dark matter — a new particle, from unknown physics beyond the Standard Model."

The team has been hunting cosmic rays with the Telescope Array experiment in Utah since 2008, and will now continue to do so with a fourfold improved sensitivity of the newly upgraded project. They also expect other next-generation observatories to get in on the cosmic-ray action to help scientists embark on a more detailed investigation of the Amaterasu particle.

"I am personally excited to have found a new mystery in science to solve," Fujii concluded.