Fomalhaut, the 18th brightest star visible in the night sky, is orbited by the compact light source Fomalhaut b, which has been previously interpreted as either a dusty exoplanet or debris from a collision of two planetesimals. While such collisions are seldom witnessed, their remnants can be captured in images. Recent observations from the NASA/ESA Hubble Space Telescope indicate that a second point source is expected to appear around Fomalhaut in 2023, reminiscent of Fomalhaut b’s appearance two decades ago. Astronomer Paul Karas from the University of California, Berkeley, and his team suggest this new source is a dust cloud resulting from a recent collision between two planetesimals.
This Hubble image shows the debris ring and dust clouds CS1 and CS2 around Fomalhaut. Image credit: NASA / ESA / P. Kalas, University of California, Berkeley / J. DePasquale, STScI.
Fomalhaut is an A-type star located a mere 25 light-years away in the constellation Austrinus Pisces.
The name Fomalhaut originates from its Arabic name, Hum Al Hat, which translates to “fish mouth.”
This star is twice as massive and 20 times more luminous than the Sun, encircled by a ring of dust and debris.
In 2008, astronomers utilized Hubble to identify a potential planet surrounding Fomalhaut, marking it as the first star system where a potential planet was detected using visible light.
The object termed Fomalhaut b presently resembles a dust cloud that appears akin to a planet, resulting from a planetesimal impact.
During new Hubble observations aimed at locating Fomalhaut b, Dr. Karas and his colleagues were astonished to discover a second point of light positioned similarly around the star.
This new object has been dubbed Stellar Frequency Source 2 (cs2), while the original object is now referred to as cs1.
“This is definitely the first instance we’ve observed a point of light spontaneously appearing in an exoplanetary system,” remarked Dr. Karas.
“Hubble images up to now have not shown this. What we’re witnessing is a violent collision between two massive bodies creating an enormous debris cloud, unlike anything else currently seen in our solar system. It’s incredible.”
The proximity of these two debris clouds remains a puzzle for astronomers.
If asteroid and planetesimal collisions were random, cs1 and cs2 should ideally be found in unrelated positions.
However, they are intriguingly located close together along the inner edge of Fomalhaut’s outer debris disk.
Another enigma is the occurrence of these two events in such a brief timespan.
“Previous theories indicated that impacts should occur roughly once every 100,000 years or more. Yet, we’ve observed two impacts in just 20 years,” Dr. Karas noted.
“If you had movies from the past 3,000 years and fast-forwarded them to make a year just a fraction of a second, imagine how many flashes you’d see during that period.”
“The Fomalhaut planetary system will continue to provide insights into these collisions.”
Collisions are crucial for the evolution of planetary systems, yet they are infrequent and challenging to study.
Dr. Mark Wyatt, an astronomer at the University of Cambridge, stated: “The intrigue of this observation lies in its ability to assist researchers in estimating the size of the impactor and the number of objects present in the disk. This data is nearly impossible to obtain through other methods.”
“We estimate that the planetesimals destroyed to form CS1 and CS2 were only around 30 km in diameter, suggesting there are approximately 300 million such objects orbiting the Fomalhaut system.”
“This system effectively serves as a natural laboratory for studying the behavior of planetesimals during collisions, enabling us to learn about their composition and formation.”
For further details, see this result. Featured in this week’s Science diary.
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Paul Kalas and colleagues. 2025. Second planetesimal impact in the Fomalhaut system. Science published online on December 18, 2025. doi: 10.1126/science.adu6266
Composite image of Fomalhaut’s dust belt (center hidden). The inset displays dust cloud cs1 taken in 2012 together with dust cloud cs2 from 2023.
NASA, ESA, Paul Karas/University of California, Berkeley
Around the star Fomalhaut, asteroids are involved in collisions that generate massive dust clouds. This is the first time astronomers are witnessing these events, offering insights into the early days of our solar system.
Fomalhaut has had its share of unusual findings. In 2008, Paul Kalas, based on observations from the Hubble Space Telescope in 2004 and 2005, reported a potential giant planet orbiting the young star. Over the years, however, the nature of this peculiar object, dubbed Fomalhaut b, has sparked heated debates. It could either be a planet slightly larger than Jupiter or simply a cloud of debris.
Now, Kalas and his team have revisited Fomalhaut using Hubble. “In 2023, we utilized the same equipment as before, and Fomalhaut b was undetectable. It was effectively gone,” says Kalas, “What appeared was a new Fomalhaut b.”
This new bright feature, named Fomalhaut CS2 (short for “circumstellar light source”), cannot be a planet, as it would have been identified earlier. The leading theory is that it represents a dust cloud resulting from the collision of two large asteroids or planetesimals, each approximately 60 kilometers in diameter. The disappearance of Fomalhaut b implies that it may have been a similar dust cloud all along.
“These sources exhibit noise and instability, so we’re still far from drawing definitive conclusions,” notes David Kipping at Columbia University. “Yet, all existing evidence aligns well with a broader narrative of collisions between protoplanets in nascent systems.”
Interestingly, it’s unexpected to observe such a significant break twice. “The hypothesis suggests that we shouldn’t witness such impacts more than once every 100,000 years, if not even more infrequently. And yet, for some unexplained reason, we seem to observe it twice within 20 years,” Kalas explains. “Fomalhaut lights up like a holiday tree and it’s astounding.”
This might indicate that collisions among planetesimals are occurring more frequently than previously thought, particularly around relatively young stars like Fomalhaut. Kalas and his team plan to conduct further observations over the next three years utilizing both Hubble and the more powerful James Webb Space Telescope (JWST) to track the behavior of Fomalhaut CS2 and attempt to pick up faint signals from Fomalhaut b.
This presents a rare opportunity to witness these collisions first-hand. “To comprehend these violent phenomena, we no longer need to rely solely on theoretical models; we can observe them in real time,” Kalas states. Further observations may enlighten us not only about young planetary systems generally but also about our own early solar system’s position in the cosmic landscape.
“We have long pondered whether the collisions that formed our moon are typical of what occurs throughout the universe, and now we have strong evidence suggesting they are indeed common,” Kipping remarked. “Perhaps we are not as unique as some may assume.”
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An artistic representation of a satellite in Earth’s orbit
Yusery Yilmaz/Shutterstock
In the event that all satellites ceased their ability to maneuver, a collision would likely happen in just 2.8 days, underscoring the dense nature of Earth’s orbital space.
Over the past seven years, the number of satellites has more than tripled, soaring from 4,000 to nearly 14,000. A significant factor driving this surge is SpaceX’s Starlink program, which currently includes over 9,000 satellites situated in low Earth orbit between 340 and 550 kilometers above our planet.
This dramatic rise necessitates that satellites frequently adjust their positions to avoid collisions, which could create thousands of metal fragments and make parts of Earth’s orbit unusable. This process is referred to as a collision avoidance maneuver.
Between Dec. 1, 2024, and May 31, 2025, SpaceX executed 144,404 collision avoidance maneuvers within the constellation, averaging one every 1.8 minutes, per company reports. Notably, there has only been one documented orbital collision. In 2009, a functioning satellite from Iridium Communications collided with a defunct Russian Cosmos satellite, leaving hundreds of debris scattered in orbit.
Sarah Thiele and researchers from Princeton University utilized publicly available satellite tracking data to simulate the impact of increasing satellite numbers on collision risk. They introduced a novel measure named the Collision Realization And Significant Harm (CRASH) Clock to evaluate this risk. The title draws parallels to the well-known Doomsday Clock, which symbolizes the imminent threat of nuclear warfare. “We discussed it extensively,” he notes. Samantha Lawler, another team member from the University of Regina in Canada, contributed to this effort.
Their findings revealed that if all satellites in orbit as of 2018 (prior to the inaugural Starlink launch in 2019) suddenly lost control, a collision would have been imminent within 121 days. Presently, due to the surge in operational satellites, this timeframe has drastically reduced to a mere 2.8 days.
“We were astonished by how short it was,” Thiele comments.
The 2.8 days assumes a scenario where an event—such as a severe solar storm—renders all satellites incapable of altering their trajectories. In May 2024, a significant solar storm caused some Starlink satellites to react dramatically. A recurrence of the Carrington Event, the strongest solar storm on record from 1859, might bring serious challenges; Wind Vatapally from Luxembourg’s SES Satellites believes not all satellites would be incapacitated at once. “It would be implausible for all of them to fail simultaneously,” he states.
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Indicators like the crash clocks serve to emphasize the congested state of Earth’s orbit, he remarks. Hugh Lewis from the University of Birmingham in the UK questions, “Can we keep piling on this precarious structure?” He adds, “The more elements you introduce, the greater the risk of a collapse when problems arise.”
With plans for tens of thousands more satellites to be launched in the coming years by SpaceX, Amazon, and various Chinese enterprises for their extensive constellations, it’s plausible that the CRASH clock will indicate an even shorter timeframe, raising the potential for collisions. “It’s quite frightening to consider,” Thiele adds.
Ryan Wills. Barry Hetherington. ESA; NASA; Adobe Stock
For over five decades, Richard Binzel has been studying the skies for potentially hazardous asteroids. In 1995, he introduced the Near-Earth Object Hazard Index, which was later renamed the Torino Scale. This scale evaluates asteroids on a scale from 0 to 10, determined by both the probability of an impact with Earth and the potential destruction that impact could cause.
This year, Binzel’s scale gained attention when asteroid 2024 YR4 briefly reached a level 3 status, marking the first time an asteroid had achieved this level in two decades. Although the immediate risks have since diminished, this event highlighted the continued necessity of the Torino Scale. Binzel, who is affiliated with the Massachusetts Institute of Technology, reassured us that such peak levels are unlikely to be reached during our lifetimes or even those of our grandchildren. He discussed with New Scientist the nuances of asteroid hunting, the risk of catastrophic collisions, and the trajectory of planetary defense.
Alex Wilkins: How was the asteroid impact risk perceived when you began your career?
Richard Binzel: I published my first paper in the 1970s. [Geologist] Eugene Shoemaker was aware that the craters on Earth were the result of impacts. Hence, I grew up understanding that asteroid impacts are a natural phenomenon still occurring today within our solar system.
Public perception was dismissive at best. While Shoemaker focused on serious scientific inquiry without much regard for public opinion, others, including astronomers Clark Chapman, David Morrison, and Don Yeomans, began acknowledging the importance of public communication. In 1989, Chapman and Morrison published Space Catastrophe, which offered one of the first serious examinations of this subject for the general public. The discovery of the KT boundary layer by Alvarez, associated with the Chicxulub asteroid that may have led to the extinction of the dinosaurs, served as a pivotal wake-up call regarding modern geological history’s potential impacts.
What prompted you to create the Near-Earth Object Hazard Index?
In 1997, an object designated XF11 exhibited a non-zero collision probability based on its initial orbit. Email was just starting to gain traction, and I was part of a small email communication group consisting of Brian Marsden, Yeomans, Chapman, and Morrison discussing how to handle this information. I was eager to publish findings but wanted to ensure accuracy regarding the risk. As further measurements of its orbit were conducted, the probability of collision was expected to fade. Why raise the alarm if the risk would likely disappear?
Marsden decided to draft a press release just as he was uncovering early observations that allowed him to conclude the collision probability was zero. I recall Yeomans sending an email stating, “Hey everyone, it’s zero.” Marsden believed it was crucial to communicate this to the public, though most of us felt we weren’t ‘crying wolf.’
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I first presented this idea at a United Nations conference, but it was not well received. “
This experience underscored the necessity of having a method of communication when an asteroid is discovered—even if small—with a non-zero collision probability. It’s crucial to be patient and acquire sufficient data to resolve uncertainties. It’s vital not to suppress information when similar objects are found elsewhere, as secrecy breeds distrust. We unanimously agreed that transparency was paramount, allowing people to understand what we knew as early as possible. This philosophy gave birth to what was initially termed the Near-Earth Object Hazard Index.
A diagram showing what the Chicxulub crater on the Yucatán Peninsula looked like immediately after the asteroid impact that may have wiped out the dinosaurs.
D. Van Ravenswaay/Science Photo Library
How was your idea received initially?
Coincidentally, I attended a United Nations conference focused on near-Earth asteroids where I first presented this concept, but it met with skepticism. Some attendees argued it was unnecessary since details about an orbit could be explained through longitude, latitude, and ascending node. They deemed a straightforward 0 to 10 scale superfluous. Arrogantly, some astronomers insisted they need not depend on it, believing they were knowledgeable enough to interpret complex three-dimensional orbital properties.
Nevertheless, I persisted. After bringing it back to the Turin conference, I decided to name it the Turin Scale. I aimed to avoid personal attribution to maintain humility; it was for collective benefit.
The Turin Scale assigns an asteroid a score from 0 to 10 based on its size and risk of hitting Earth.
Was the outcome as you expected?
I anticipated more activity than what we’ve observed, likely due to the effective tracking methods in place for objects. If there’s a non-zero probability associated with an object, it typically gets sorted out quickly.
Over a dozen objects have achieved a score of 1 on the Turin scale with minimal publicity, but that’s precisely as intended. It’s akin to the Richter scale; when Californians learn they might experience a magnitude 1 or 2 earthquake, it doesn’t disrupt their day.
What does the future hold for asteroid tracking?
The pace of near-Earth asteroid discovery is set to surge with the operational launch of the Vera C. Rubin Telescope and the Near-Earth Object (NEO) survey telescope. We’ll identify these objects at an unprecedented rate. Some will possess highly uncertain initial trajectories that require extensive extrapolation, resulting in non-zero collision probabilities. It will take time to gather ample orbital data and assert where these objects will be decades into the future, fully ruling out any collision risks.
We may encounter objects that reach levels like 4 or 5 on the Turin scale, but the true threat level remains out of the ‘red zone.’ I doubt we’ll see such instances in anyone’s lifetime, or even our great-grandchildren’s. These events are incredibly rare. However, there are mechanisms for the public to recognize what to monitor and what to disregard.
As for lower scores on the Turin scale, they will become so routine that they will no longer garner public attention. People can trust astronomers to track interesting objects and ensure their eventual disappearance. The Turin Scale has fulfilled its purpose.
Asteroid 2024 YR4 reached a value of 3 on the Turin scale and then dropped to 0.
NASA/Magdalena Ridge 2.4m Telescope/NMT
Was the Torino system effective during the incident with asteroid 2024 YR4 reaching level 3?
My colleague articulated the message effectively, reiterating that as we collected more data, we anticipated the object would become less concerning. This was our constant reassurance. The descriptions of the categories on the Turin Scale offer insights valuable to astronomers. We were highly confident that further data would eliminate Earth impact possibilities.
The confusion among the media and the public stemmed from misunderstanding the impact probability, which was consistently low. (At its peak, 2024 YR4 had a 3.1 percent impact probability.) As more data came in, the probability fluctuated—this is a natural outcome based on expanding our understanding. Initially, we observed an asteroid over a short trajectory, but extrapolating that trajectory significantly into the future could sometimes indicate higher projections. This increase was more of an adjustment process than a sign of danger.
What can you tell us about Apophis? It’s a 340-meter asteroid expected to come remarkably close to Earth in 2029 but is projected to miss. What gives us such confidence?
When discussing Apophis, I provide three key reassurances: Apophis will safely pass Earth. Apophis will safely pass Earth. Apophis will safely pass Earth. The confidence stems from over two decades of precise tracking, including radar signals reflecting off the asteroid to pinpoint its position within a meter. The margin of uncertainty regarding its close pass is a mere plus or minus 3 kilometers.
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If we need to take action to mitigate an incoming asteroid, we possess the ability, provided we have sufficient time. “
Astronomers have been taking this object very seriously for the last 20 years. Initially, when it was discovered, it had a rating of 4 on the Turin scale, a unique occurrence for any object. However, it was only for a brief duration, maybe just a week, around Christmas 2004 when the asteroid attracted significant attention. I wanted to nickname it “The Grinch” since I was up late on Christmas Eve scrutinizing asteroid orbits until my family pulled me away.
NASA’s DART mission, which aimed to change an asteroid’s orbit, signifies a new chapter for planetary defense. How crucial was this mission?
DART represents a leap forward in our evolution as a species. No longer are we entirely at the mercy of the cosmos. DART illustrated our capacity to target and alter an object’s trajectory. This is a defining moment for humanity, asserting that if we need to counter an asteroid’s approach, we have the capabilities to do so—given we have the time.
Many still voice concerns about the threat of a giant asteroid potentially eradicating humanity. How has this perception evolved since your early involvement in the field?
We are making strides. It’s not an overwhelming concern; rather, it’s a manageable risk that we’ve come to better understand. Personally, after dedicating 50 years of my life as a scientist mostly funded by public resources, I feel a moral duty to advocate for the necessity of detecting serious asteroid threats, thereby fulfilling our responsibilities as scientists.
To illustrate, if we were unexpectedly surprised by an asteroid that we could have detected had we invested in telescopes a decade ago, it would signify a monumental oversight in scientific history. This is the primary frustration I harbor regarding asteroids: the idea that we haven’t fully done our jobs.
As Vera Rubin and the NEO surveyors become operational, it marks a significant advancement. We’re finally in a position to conduct thorough assessments and determine the potential threats posed by asteroids in the coming epochs. With our capacity to seek answers, it’s our responsibility to pursue them.
New Polana Collisional Family The primary asteroid belt in our solar system is the source of insights about nearby asteroids (101955) Bennu and (162173) Ryugu, which are the focus of NASA’s Osiris Rex missions. Currently, astronomers utilizing the NASA/ESA/CSA James Webb Space Telescope are gathering spectroscopic data from the family progenitor, (142) Polana, and comparing it to laboratory data from both spacecraft and near-Earth asteroids, revealing near-infrared spectral similarities that lend support to the hypothesis that they originated from the same protoplanetary body.
This image of this asteroid was captured on June 26, 2018 by Jaxa’s Hayabusa-2 Spacecraft optical navigation camera – telescopic (ONC-T). Image credits: Jakusa / University of Tokyo / Kochi University / Ricchiho University / Nagoya University / Chiba University of Technology / Nishimura University / Aizu University / AIST.
“We hypothesize that in the early formation of our solar system, a significant asteroid collided and broke apart, creating the Polana and the ‘Asteroid Family,’ the largest remaining body,” stated Dr. Anisia Aredondo, a researcher at the Southwest Research Institute.
“This theory posits that the remnants of that collision led to the formation of not just Polana, but also Bennu and Ryugu.”
“To validate this theory, we began analyzing the spectra of all three entities and comparing them.”
The researchers used time on Webb to observe Polana with two different spectral instruments targeting near-infrared and mid-infrared wavelengths.
The data was then contrasted with spectral information from physical samples of Ryugu and Bennu collected by two distinct space missions.
“Bennu and Ryugu are categorized as near-Earth asteroids as they orbit the Sun within Mars’ orbit,” they noted.
“However, they pose no threat to our planet, with closest approaches of approximately 3 million km (1.9 million miles) and 1.6 million km (1 million miles), respectively.”
“Bennu and Ryugu are relatively small compared to Polana; Bennu measures about 500 m in diameter (0.3 miles), while Ryugu is twice as large, but both Polana and Ryugu measure about 55.3 km (34.4 miles) wide.”
“Scientists believe that Jupiter’s gravity caused Bennu and Ryugu to drift out of their orbit near Polana.”
“Given their similarities, I am confident all three asteroids share a common parent,” she added.
This mosaic image of the asteroid Bennu consists of 12 images collected on December 2, 2018 by a 15-mile (24 km) Polycam instrument at Osiris-Rex. Image credit: NASA/NASA’s Goddard Space Flight Center/University of Arizona.
The authors indicate that while spectral data from the asteroids exhibit variations and discrepancies, they do not sufficiently invalidate the hypothesis that they all have a shared origin.
“Polana, Bennu, and Ryugu have been traversing their respective paths through our solar system since the collision that may have formed them,” remarks Dr. Tracy Becker from the Southwest Research Institute.
“Bennu and Ryugu are now much closer to the Sun compared to Polana, resulting in their surfaces being more influenced by solar radiation and solar particles.”
“Additionally, Polana is likely older than Bennu and Ryugu, and as such, has been subjected to impact from micrometeorites over an extended period.”
“This could potentially alter the surface areas containing their elemental compositions.”
A study detailing the survey results has been published in the Journal of Planetary Science.
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Anisia Aredondo et al. 2025. Planet. Sci. J. 6, 195; doi:10.3847/psj/ade395
New records for black holes have transformed our understanding of the universe’s most extreme entities.
The Laser Interferometer Gravitational-Wave Observatory (LIGO) began its groundbreaking detection of gravitational waves—ripples in the fabric of spacetime—ten years ago, unveiling nearly 100 black hole collisions. On November 23, 2023, Rigo announced receiving a signal described as “an extraordinary interpretation that defies explanation.” According to Sophie Binnie from the California Institute of Technology, her team ultimately concluded that it corresponded to the largest black hole merger ever recorded.
One of the merging black holes was approximately 100 times the mass of the sun, while the other neared 140 solar masses. Previous records featured black holes that were almost half as massive, primarily due to earlier mergers. Team member Mark Hannam from Cardiff University, UK, emphasized that these black holes were not only immense but also spinning at such high speeds that they challenged mathematical models of the universe regarding their formation.
According to Hannam, the masses of these black holes exceed those typically formed from the collapse of aging stars, suggesting they likely resulted from earlier mergers between smaller black holes. “It’s possible that multiple mergers have occurred,” he notes.
“A decade ago, we were astonished to find black holes around 30 solar masses. Now, we observe black holes over 100 solar masses,” adds Davide Gerosa from the University of Bicocca in Milan, Italy. He mentions that gravitational wave signals from these large, quickly rotating black holes are shorter and consequently more challenging to detect. Binnie presented her findings at the Edoardo Amaldi Conference on Gravitational Waves in Glasgow, England, on July 14.
Both Hannam and Binnie emphasize that future observations of similarly remarkable mergers are essential to further decipher these new signals, including unraveling the origins of black holes. As upgrades progress, LIGO is expected to detect more cosmic record-breakers. Yet, in May, the Trump administration proposed halving resources at the facility, which, in Hannam’s opinion, could render capturing new signals exceedingly difficult.
Asteroid 2024 YR4 may create the largest lunar impact in the past 5,000 years
Mark Garlic/Science Photo Library/Getty Images
Originally believed to be on a collision path with Earth, asteroid 2024 YR4 still poses some level of threat to our planet. There remains a chance that such celestial bodies could impact the moon, potentially resulting in a catastrophic explosion that could flood Earth with debris capable of damaging satellites.
Astronomers have been monitoring this building-sized asteroid since its detection in December 2024. Initial forecasts heightened the risk of a collision with Earth in 2032, suggesting the impact could unleash enough energy to obliterate a city; fortunately, it now appears 2024 YR4 will likely miss us.
Nonetheless, the likelihood of a lunar impact is gradually increasing, currently estimated at 4.3% based on observations made before the asteroid moved out of our telescopes’ view until 2028. Paul Wiegelt from the University of Western Ontario and his team suggest that such a collision could inflict significant damage on Earth’s satellites.
“We were somewhat taken aback by the amount of debris that could potentially reach Earth,” Wiegert remarked. “In reality, Earth is a surprisingly small target from the moon’s vantage point. Thus, while impacts on Earth are infrequent, gravitational forces can draw in that material under certain conditions.”
Wiegert and his colleagues calculated that 2024 YR4 could create a crater over a kilometer wide on the moon, marking the largest lunar impact in at least the last 5,000 years, albeit still small compared to typical craters. By ejecting debris into space and simulating their trajectories tens of thousands of times, they concluded that this event could lead to collision rates for Earth’s satellites comparable to those observed over years or even days.
While these collisions may not entirely disable a satellite, they could cause significant anomalies due to electrical disruptions. Accurately modeling their potential damage proves challenging, Wiegert noted.
If luck is not on our side, the impact of fragmented materials could be particularly severe, according to Mark Burchell at the University of Kent in the UK. “If they impact a spacecraft’s coolant pipe or an exposed sensor, the loss of critical functions occurs suddenly,” he explained. “Once damaged, satellites cannot be repaired. Even minor issues can lead to serious problems.”
Wiegert emphasized that this scenario should provoke global space agencies to consider deflecting asteroids on a collision course with the moon, similar to efforts aimed at protecting Earth. A NASA Planetary Defense Coordination Agency representative stated that while it is crucial to identify Near-Earth Objects (NEOs) posing potential risks, it is “premature to speculate on possible response options” for a potential 2024 collision.
Depending on how events unfold, swift action could be necessary. When 2024 YR4 reappears in Earth’s telescopic view in 2028, we should be able to refine the precision of its orbital path, Wiegert commented. As chances for a lunar impact rise, it offers a four-year window for decision-making on any necessary actions.
“That’s the million-dollar question,” he remarked. “I don’t have a very satisfactory answer.”
There are three distinct types of Sargassum found in the Caribbean and surrounding regions, buoyed by small air sacs, which makes their presence truly remarkable. According to Burns, scientists are currently observing various factors influencing its growth, which depend on sunlight, nutrients, and water temperature.
Experts also point to agricultural runoff, warmer waters, and alterations in wind, currents, and rainfall as factors that can have an impact.
Large mats of algae in the open ocean create what Burns refers to as a “healthy and thriving ecosystem,” home to species ranging from tiny shrimp to endangered sea turtles. However, Sargassum close to shore can wreak havoc.
It can block sunlight essential for coral reefs and seagrasses, and when the algae sink, they may suffocate these ecosystems. Once washed ashore, the organisms that inhabit the algae either perish or are scavenged by birds, according to Burns.
The massive piles of odorous seaweed pose a significant challenge for the Caribbean, especially since tourism is a vital economic driver for many small islands.
“It’s a hurdle, but it hasn’t impacted every corner of the Caribbean,” said Frank Comitto, a special advisor to the Caribbean Hotels and Tourism Association.
At a popular tourist destination in Punta Cana, Dominican Republic, officials have invested in barriers to keep Sargassum from reaching the beaches, he noted.
In St. Maarten’s Dutch Caribbean territory, teams equipped with backhoes were mobilized for an emergency cleanup after residents reported a strong ammonia and hydrogen sulfide odor.
“The smell is quite unpleasant,” Burns stated.
Meanwhile, in the French Caribbean, officials plan to quickly utilize storage barges and specialized vessels capable of collecting several tons of seaweed daily.
Sargassum “will harm our coastlines, hinder swimming, and create unbearable living conditions for local residents,” French Prime Minister François Beilou recently informed the press.
However, Comitto mentioned that employing such vessels is “very costly” and not widely accepted, while an alternative method (using heavy machinery) is labor-intensive.
“We must tread carefully, as sea turtle eggs might be affected,” he advised. “You can’t just go there and bulldoze everything away.”
As some Caribbean islands face financial challenges, most cleanup efforts fall to hotels, with certain guests receiving refunds and complimentary shuttles to unaffected beaches.
Each year, the volume of Sargassum increases at the end of spring, peaks during summer, and then starts to decline in late autumn or early winter, noted Burns.
The recent record levels remain relatively stationary. Experts are hopeful for more Sargassum in June.
The Milky Way galaxy is often believed to be on a collision path with the neighboring Andromeda galaxy. This merger, anticipated roughly 5 billion years in the future, is expected to create a new elliptical galaxy. However, recent studies indicate that the likelihood of such a catastrophic event may be less than previously assumed.
These images depict three encounter scenarios between the Milky Way galaxy and the neighboring Andromeda galaxy. Top left: Messier 81 and Messier82. TopRight: NGC6786. BOTTOM: NGC 520. Image credits: NASA/ESA/STSCI/DSS/Till Sawala, Helsinki University/Joseph Depasquale, STSCI.
The Milky Way navigates through space, its trajectory affected by the gravitational forces from nearby galaxies, including Andromeda, Triangulum, and the Large Magellanic Cloud.
Consequently, prior studies have proposed for over a decade that the Milky Way is likely to collide with Andromeda, forming a new elliptical galaxy referred to as Milkomeda in about 5 billion years.
Dr. Thiru Sawara, an astronomer at the University of Helsinki, stated:
In their latest research, Dr. Sawara and colleagues utilized updated data from the ESA Gaia satellite and the NASA/ESA Hubble Space Telescope to model the Milky Way’s movement through space over the next 10 billion years, while also refining estimates of the masses of local galaxies.
They discovered that there is about a 50% chance that no collision will occur between the Milky Way and Andromeda during this time frame.
The authors suggest that previous analyses overlooked certain calculations and uncertainties, including the gravitational influence of the Large Magellanic Cloud (a smaller galaxy orbiting the Milky Way).
They also propose that a merger with the Magellanic Clouds is nearly certain within the next two billion years, prior to any potential interaction with Andromeda.
“Even with the latest and most precise observational data at hand, the future of local galaxy groups remains uncertain,” Dr. Sawara remarked.
“Interestingly, there are roughly equal probabilities of widely discussed merger scenarios or, conversely, scenarios where the Milky Way and Andromeda remain unaffected.”
The team’s findings will be featured this week in the journal Nature Astronomy.
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T. Sawara et al. There is no certainty regarding the Milky Way and Andromeda collision. Nature Astronomy. Published online on June 2, 2025. doi:10.1038/s41550-025-02563-1
Analysis from the ESO’s Very Large Telescope (VLT) and ALMA data indicates that intense radiation from a quasar within these galaxies affects the gas properties of other galaxies, reducing their ability to form new stars.
Artistic impression of a galaxy merger where the right galaxy hosts a quasar at its core. This quasar, containing a supermassive black hole, emits a powerful radiation cone that affects neighboring galaxies. This interaction can destroy gas and dust clouds, leaving behind only denser regions that may struggle to form stars. Image credit: ESO/M. Kornmesser.
“In the far reaches of the universe, two galaxies are entangled in an exhilarating conflict,” remarked Dr. Paschier Notardem, an astronomer affiliated with the Paris Astronomical Institute.
“On a collision course at speeds of 500 km/s, they collide multiple times, only to push one another away before gearing up for another round.”
“Thus, we refer to this system as the ‘space joust.’ However, these galactic contenders don’t fight fairly, utilizing quasars to strike with beams of radiation.”
Quasars are the luminous cores of certain distant galaxies powered by supermassive black holes, emitting substantial amounts of radiation.
The combination of a quasar with a galaxy was significantly more common during the universe’s first billion years, allowing astronomers to glimpse the remote past using powerful telescopes.
The light from this “joust of the universe” traveled over 11 billion years to reach us, providing a snapshot of the universe when it was merely 18% of its current age.
ALMA image showcasing the molecular gas content of two galaxies involved in a collision. Image credits: ALMA/ESO/NAOJ/NRAO/Balashev et al.
“According to Dr. Sergei Balashev from the Ioffe Institute,
the observations from the new VLT/ALMA indicate that radiation from the quasar J012555.11-012925.00 obliterates the normal gas and dust clouds in the surrounding galaxy, leaving only the densest regions.
These regions are likely too limited for star formation, causing a significant decline in stellar nurseries within the affected galaxy.
However, the transformed galaxies are not the only ones undergoing changes.
“These mergers are believed to funnel substantial amounts of gas into the supermassive black holes at the galaxies’ centers,” Dr. Balashev mentioned.
“In this cosmic arena, fresh supplies of fuel come within reach of black holes that power the quasar.”
“As these black holes are nourished, the quasar can persist in its destructive assault.”
A paper detailing these findings was published today in the journal Nature.
____
S. Balashev et al. Quasar radiation transforms gas in a merged companion galaxy. Nature Published online on May 21, 2025. doi:10.1038/s41586-025-08966-4
Discarded Soviet-era spacecrafts do not pose a significant risk to Earth, according to experts.
The Kosmos-482, initially designed for a mission to land on Venus, has been stuck in Earth’s orbit for 53 years due to rocket issues. It is anticipated to re-enter the Earth’s atmosphere in the coming days, with the latest forecasts predicting an uncontrolled descent on Saturday.
While the sight of large metal fragments falling back to Earth might seem alarming, old satellites and rocket debris actually re-enter the atmosphere almost daily. According to the European Space Agency (ESA), such events are quite common.
Typically, spacecraft burn up harmlessly upon re-entry. Even if some components survive the intense heat, it is rare for them to land on populated areas, mainly due to the fact that oceans cover about 71% of the Earth’s surface.
“The likelihood of a satellite re-entering and causing injury is exceedingly low,” noted an ESA official in Blog entries regarding Kosmos-482. “Statistically, an individual has less than a one in 100 billion chance of being harmed by space debris. In contrast, a person is approximately 65,000 times more likely to be struck by lightning.”
ESA’s Space Debris Office predicts that Kosmos-482 will start its descent around 4:26 AM on Saturday, with a possible variance of ±4.35 hours.
Meanwhile, U.S. space forces anticipate an earlier re-entry time of about 1:52 AM on Saturday.
The specific re-entry trajectory remains uncertain due to atmospheric dynamics, space weather, and orbital decay, complicating the task of accurately predicting when and where an uncontrolled spacecraft will land.
As the spacecraft nears re-entry, predictions may become more reliable, but pinpointing the exact landing site remains challenging.
NASA has indicated that the potential landing area could be “52 N-52 seconds latitude,” a vast expanse that includes much of Africa, Australia, North America, South America, and parts of Europe and Asia.
Officials from the Space Force have stated that current projections suggest Kosmos-482 will re-enter the Pacific Ocean, west of Guam, landing south of Australia, possibly over or near the southern ocean.
Launched by the Soviet Union in 1972, Kosmos-482 was part of a mission aimed at landing on Venus but ended up in orbit around Earth following a rocket failure.
While most of the debris from this ill-fated mission returned to Earth decades ago, the spherical landing capsule is anticipated to descend this weekend.
This capsule, measuring around 3 feet in diameter, was engineered to withstand the extreme conditions of Venus, raising questions about its capacity to survive re-entry into Earth’s atmosphere, as highlighted by Marco Langbroek, a scientist from the Delft Institute of Technology in the Netherlands, who has been monitoring Kosmos-482 and posting updates online.
“Even if it manages to re-enter, there’s a chance that it might collide intact,” Langbroek noted in a blog update on Thursday. “However, the impact could be severe, and I highly doubt the parachute deployment system will function after 53 years of battery drainage.”
Nonetheless, this does not imply that coastal populations are at imminent risk.
“While the risks are not exceedingly high, they aren’t nonexistent. With masses under 500 kg and impacts resembling those of meteorites, the probabilities are similar,” he wrote.
The generation of top quark pairs is observed This process of interaction between atomic nuclei was observed for the first time in lead-lead collisions at CERN's Large Hadron Collider (LHC) and the ATLAS detector.
We show lead-lead collisions at 5.02 TeV per nucleon pair, resulting in the production of candidate pairs of top quarks that decay into other particles. This event contains four particle jets (yellow cone), one electron (green line), and one muon (red line). The inlay shows an axial view of the event. Image credit: ATLAS/CERN.
In quark-gluon plasma, quarks (matter particles) and gluons (strong force transmitters), which are the basic constituents of protons and neutrons, are not bound within particles and exist in an unconfined state of matter, and almost It forms a complete dense fluid.
Physicists believe that quark-gluon plasma filled the universe shortly after the Big Bang, and their study provides a glimpse into conditions at earlier times in the universe's history.
However, the lifespan of quark-gluon plasma produced by heavy ion collisions is extremely short, approximately 10 years.-twenty three Seconds — means not directly observable.
Instead, physicists study the particles produced in these collisions that pass through the quark-gluon plasma and use them as probes of the plasma's properties.
In particular, the top quark is a very promising probe of the evolution of quark-gluon plasmas over time.
The top quark, the heaviest elementary particle known, decays into other particles an order of magnitude faster than the time required to form a quark-gluon plasma.
The delay between the collision and the decay products of the top quark interacting with the quark-gluon plasma may serve as a “time marker” and provide a unique opportunity to study the temporal dynamics of the plasma.
In addition, physicists could potentially extract new information about the nuclear parton distribution function, which describes how the momentum of a nucleon (proton or neutron) is distributed among its constituent quarks and gluons.
In the new study, physicists from the ATLAS collaboration studied lead ion collisions that occurred during LHC Experiment 2 at a collision energy of 5.02 teraelectronvolts (TeV) per nucleon pair.
They observed the production of a top quark in a dilepton channel, where the top quark decays into a bottom quark and a W boson, which then decays into an electron or muon and its associated neutrino.
This result has statistical significance with a standard deviation of 5.0, and is the first observation of the production of a top quark pair in a nucleus-nucleus collision.
“We measured the production rate, or cross section, of the top quark pair with a relative uncertainty of 35%,” the physicists said.
“The overall uncertainty is primarily driven by the size of the dataset, which means new heavy ion data from the ongoing Experiment 3 will improve the accuracy of the measurements.”
“The new results open the door to the study of quark-gluon plasmas,” the researchers added.
“Future studies will also consider semi-leptonic decay channels for top quark pairs in heavy ion collisions. This may provide the first glimpse of the evolution of quark-gluon plasmas over time.” ”
Approximately 50,000 collision avoidance maneuvers were performed by satellites in SpaceX’s Starlink constellation in the first half of 2024. This number reflects the growing concern about satellite collisions as the number of satellites orbiting the Earth continues to increase unchecked.
With a significant portion of our communication, navigation, and climate change observation relying on space infrastructure, the potential for a catastrophic collision that could disrupt these critical services is a valid concern.
Space debris resulting from collisions poses a significant risk to operational satellites. Previous incidents, such as the 2009 collision between the U.S. satellite Iridium 33 and the Russian spacecraft Cosmos 2251, highlight the potential dangers of high-speed collisions in orbit.
As the number of satellites in orbit continues to rise, the risk of collisions and conjunctions also increases. Flybys between satellites, like the ones observed by LeoLabs, underscore the potential for catastrophic events that could generate significant amounts of debris in space.
Efforts to prevent collisions, such as onboard software maneuvers and tracking systems, are crucial in mitigating risks. However, as more satellites are launched, concerns remain about the software’s ability to handle the increasing volume of space objects.
The rise in satellite constellations, driven by companies like Starlink aiming to provide global internet coverage, exacerbates the collision risk. The challenge now is to balance the benefits of satellite technology with the potential hazards it poses to orbital space, astronomy, and the environment.
As the debate continues on how to manage the growing number of satellites and ensure the sustainability of outer space, the need for international cooperation and responsible satellite deployment becomes increasingly evident.
Ultimately, the future of space exploration and satellite operations hinges on finding a delicate balance between technological progress and ensuring the long-term health and safety of our activities in space.
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To orbit the Earth, a satellite must travel at a minimum speed of 7.8 km/s (4.8 miles per second), highlighting the immense energy released in a potential collision. The increasing density of satellites in orbit raises concerns about the risks posed by collisions and close encounters between space objects.
As technology advances and more satellites are launched into space, the need for responsible space debris management becomes paramount in ensuring the sustainability of future space missions and satellite operations.
Satellite collisions can scatter thousands of pieces of debris into orbital space around Earth – Image courtesy of Alamy
The increasing number of satellites in orbit not only poses risks to operational spacecraft but also interferes with astronomical observations and environmental concerns. Balancing the benefits of satellite technology with the potential hazards it poses to space and the environment is crucial in the era of rapid space exploration and commercial satellite deployment.
As we navigate the complexities of space governance and responsible satellite deployment, collaboration among stakeholders, regulators, and operators will be essential in ensuring the sustainability and safety of our activities in space.
The future of satellite operations and space exploration depends on our ability to address these challenges effectively and ensure a secure and sustainable space environment for future generations.
A blend of exposures showing thousands of satellites swarming the night sky in 2022 – Photo credit: Alan Dyer/VW Pics/Universal Images Group via Getty Images
As we continue to expand our presence in space, it becomes increasingly important to consider the implications of our actions on the environment, astronomy, and the sustainability of future space activities. By addressing these challenges collaboratively and responsibly, we can pave the way for a safer, more sustainable future in space exploration and satellite operations.
obscure our view of the universe
The proliferation of satellites around Earth presents challenges to astronomers, with concerns about interference with observations and radio signals. Finding a balance between technological progress and preserving the integrity of astronomical research is a key concern in the evolving landscape of space exploration.
As we strive to harness the benefits of satellite technology while mitigating its potential risks, it is essential to prioritize international cooperation and sustainable practices in satellite deployment and space exploration. By working together to address these challenges, we can ensure a brighter and more sustainable future in space.
Using the Atacama Large Millimeter/submillimeter Array (ALMA) and the Subaru Telescope, astronomers have discovered a merging pair of gas-rich galaxies that existed 12.8 billion years ago and housed a faint central quasar that may be the ancestor of some of the brightest and most massive quasars in the early universe.
Artist's impression of the quasars HSC J121503.42-014858.7 and HSC J121503.55-014859.3. Image courtesy of Izumi others., doi:10.3847/1538-4357/ad57c6.
Quasars are luminous objects that gained energy from matter falling into supermassive black holes at the centers of galaxies in the early universe.
The most accepted theory is that when two gas-rich galaxies merge to form one larger galaxy, the gravitational interaction between the two galaxies causes gas to fall towards a supermassive black hole in one or both of the galaxies, triggering quasar activity.
To test this theory, Dr. Takuma Izumi of the National Astronomical Observatory of Japan used ALMA to study the oldest known pair of close quasars.
The quasars, named HSC J121503.42-014858.7 and HSC J121503.55-014859.3, were discovered by the Subaru Telescope's Hyper Suprime-Cam.
These objects are very faint, about 10 to 100 times fainter than highly luminous quasars at the same redshift.
“It is located approximately 12.8 billion light-years away, corresponding to the 'cosmic dawn' era when the universe was only 900 million years old, making it the farthest such quasar pair on record,” the astronomers said.
“Because of their faintness, we thought these objects were in the pre-merger stage, before the supermassive black holes rapidly grow.”
“However, observations with the Subaru Telescope only provide information about the central supermassive black hole, and it remains unclear whether the host galaxy is destined to merge and ultimately grow into a luminous quasar.”
“As a next step, we used the ALMA radio telescope to carry out observations of the host galaxies of these quasar pairs.”
“The results were surprising: the observed distribution of interstellar material and the nature of its motions indicated that these galaxies are interacting with each other.”
“They are definitely on a path to merge into one galaxy in the near future.”
“Furthermore, calculations from observational data reveal that the total gas mass of these galaxies – about 100 billion times the mass of the Sun – is comparable to or exceeds the gas mass in the host galaxies of most luminous quasars, which have extremely bright cores.”
“This enormous amount of matter should easily trigger and sustain the post-merger burst of star formation and fueling of the supermassive black hole.”
“These discoveries therefore represent a significant achievement in identifying the ancestors of luminous quasars and starburst galaxies, the most luminous objects in the early universe, from various perspectives, including galactic structure, motion and the amount of interstellar material.”
Takuma Izumi others2024. Gas-rich galaxy merger harboring a low-luminosity twin quasar at z = 6.05: a likely progenitor of the most luminous quasars. ApJ 972, 116;doi:10.3847/1538-4357/ad57c6
To prevent a fate similar to the dinosaurs, The European Space Agency (ESA) has initiated work on a groundbreaking planetary defense mission known as the Rapid Apophis Mission for Space Security (RAMSES).
RAMSES is designed to rendezvous with 99942 Apophis, an asteroid the size of a cruise ship, and accompany it as it approaches Earth in April 2029.
Apophis, with a diameter of about 375 meters, will pass within 32,000 kilometers of Earth’s surface on April 13, 2029. This rare event will be visible to the naked eye in parts of Europe, Africa, and Asia, attracting global attention. An asteroid of this size only comes this close once every 5,000 to 10,000 years.
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Astronomers believe that Apophis is unlikely to collide with Earth in the next 100 years, but the 2029 flyby will provide scientists with a unique opportunity to observe a close encounter.
The ESA’s Ramses spacecraft is set to reach Apophis two months before the closest approach, allowing monitoring of any physical changes to the asteroid caused by Earth’s gravity.
Ramses is scheduled to launch in April 2028 and arrive at Apophis by February 2029. The mission aims to observe and study how Earth’s gravity affects Apophis, potential landslides, and any new material beneath the asteroid’s surface.
Patrick MichelGerry McClellan, CNRS Director of Research at the Observatory of the Côte d’Azur, emphasized the significance of the mission, stating: “There is much we still don’t know about asteroids, but now, nature is bringing one to us to conduct the experiment itself. All we need to do is watch as Apophis is stretched and compressed by powerful tidal forces.”
Ramses will utilize a variety of scientific instruments to comprehensively study Apophis, analyzing its shape, surface, orbit, rotation, and more.
The collected data will be closely examined by scientists to understand the asteroid’s composition, structure, and how to deflect potentially hazardous asteroids in the future.
Experts predict that Earth’s tidal forces could alter the asteroid’s rotation, potentially causing earthquakes and landslides. They hope that Ramses’ flyby will offer detailed observations of how Apophis is affected by the close encounter.
Additionally, NASA is redirecting its OSIRIS-REx spacecraft (now renamed OSIRIS-APEX) towards Apophis, set to arrive about a month after the 2029 flyby.
OSIRIS-REx was the first US mission to collect samples from an asteroid, returning material from Bennu to Earth in September 2023. After successfully delivering the sample, the spacecraft was renamed OSIRIS-APEX for its new mission to explore Apophis.
“Ramses will demonstrate humanity’s capability to deploy a reconnaissance mission to rendezvous with an approaching asteroid in just a few years,” said Richard Moisle, head of ESA’s Planetary Defence Division.
A decision on the full implementation of Ramses will be made at ESA’s Ministerial Council meeting in November 2025. If approved, Ramses will not only enhance knowledge of asteroid deflection but also provide valuable scientific insights into the solar system’s formation and evolution.
Astronomers using the NASA/ESA/CSA James Webb Space Telescope discovered a giant asteroid impact around Beta Gactris, the second brightest star in the constellation Scorpio.
Chen othersBeta Pictoris has a dynamic circumstellar environment, suggesting that periods of active collisions could produce large dust clouds that could blow through the planetary system and increase dust accretion to the giant planets Beta Pictoris b and c. Image credit: Roberto Molar Candanosa / Johns Hopkins University / Lynette Cook / NASA.
Beta Pictoris is an A5 type star located in the constellation Pictoris, approximately 63 light years from Earth.
The star has a mass about 1.8 times that of the Sun and is only 20 million years old.
It contains a circumstellar disk of gas and dust, numerous comet-like objects, and two giant planets, Beta Pictoris b and Beta Pictoris c.
Beta Pictoris b is a gas giant with a mass about 9-13 times that of Jupiter. It orbits its parent star at a distance of 9.8 astronomical units (AU) and completes one revolution around its parent star every 22 years.
Beta Pictoris c has a mass 8.2 times that of Jupiter and is located quite close to its star, orbiting it at a distance of 2.7 AU with an orbital period of about 1,200 days.
“Beta Pictoris is at an age where terrestrial planetary belt planet formation is still ongoing due to giant asteroid impacts, so what we're seeing here is essentially how rocky planets and other objects are forming in real time,” said Dr Christine Chen, an astronomer at Johns Hopkins University.
By comparing the new data with data from the Webb Space Telescope in 2004 and 2005, Dr Chen and his colleagues found a significant change in the energy characteristics emitted by the dust particles around Beta Pictoris.
Webb's detailed measurements allowed the researchers to track the composition and size of dust particles in the very region that Spitzer had previously analyzed.
The researchers focused on heat given off by crystalline silicates – minerals commonly found around young stars, on Earth and other celestial bodies – and found no trace of the particles observed in 2004 and 2005.
“This suggests that a catastrophic collision occurred between the asteroid and another object about 20 years ago, shattering the asteroid into microscopic dust particles smaller than pollen or powdered sugar,” Dr Chen said.
“We believe the dust is the same as that first observed in Spitzer data in 2004 and 2005.”
“The best explanation given by Webb's new data is that we have in fact witnessed the aftermath of a rare catastrophe between large, asteroid-sized objects, completely changing our understanding of this solar system.”
The new data suggests that dust dispersed outward by radiation from the system's central star can no longer be detected.
Initially, dust near the star heated up and emitted thermal radiation that Spitzer's instruments identified.
Now, as the dust cools away from the star, it no longer emits its thermal properties.
When Spitzer collected its previous data, scientists assumed that small objects abrading the ground would stir up the dust and steadily replenish it over time.
But Webb's new observations showed that the dust had disappeared and not been replaced.
“The amount of dust kicked up is about 100,000 times the size of the asteroid that wiped out the dinosaurs,” Dr Chen said.
According to physicists, CMS cooperation This is the first time this process has been observed in proton-proton collisions at CERN's Large Hadron Collider (LHC). This is also the most accurate measurement of tau's anomalous magnetic moment and provides a new way to constrain the existence of new physics.
We reproduced candidate events of the γγ →ττ process in proton-proton collisions measured by the CMS detector. Tau can decay into muons (red), charged pions (yellow), and neutrinos (not visible). Energy is stored in green in an electromagnetic calorimeter and cyan in a hadronic calorimeter. Image credit: CMS Collaboration.
of TauIt is a special particle of the lepton family, also called tauon.
In general, leptons, together with quarks, constitute the matter content of the Standard Model.
Tau was first discovered in the 1970s, and its associated neutrino (tau neutrino) was discovered by Fermilab's DONUT collaboration in 2000 to complete the tangible matter part.
However, tau has a very short lifetime and can remain stable for only 290*10 hours, making it quite difficult to study it accurately.-15 seconds.
Two other charged leptons, electrons and muons, are fairly well studied.
Much is also known about their magnetic moments and their associated anomalous magnetic moments.
The former can be understood as the strength and direction of a virtual bar magnet within the particle.
However, this measurable quantity requires correction at the quantum level resulting from the virtual particles pulling on the magnetic moment and deviates from the predicted value.
The quantum correction, called the anomalous magnetic moment, is about 0.1%.
If the theoretical and experimental results do not agree, this anomalous magnetic momentIopens the door to physics beyond the Standard Model.
The anomalous magnetic moment of the electron is one of the most accurately known quantities in particle physics and is in perfect agreement with models.
Its muon counterpart, on the other hand, is one of the most studied, and research is ongoing.
So far, theory and experiment are largely in agreement, but recent results raise tensions that require further investigation.
But for Tau, the race is still on. Its anomalous magnetic moment is particularly difficult to measure.τThis is because tau has a short lifespan.
The first attempt wasτ After the discovery of tau, there was an uncertainty 30 times higher than the size of the quantum correction.
Experimental efforts at CERN improved the constraints and reduced the uncertainty to 20 times the size of the quantum correction.
In collisions, physicists look for special processes. That is, two photons interact to produce two tau leptons (also called a ditau pair), which then decay into muons, electrons, or charged pions, and neutrinos.
So far, both ATLAS and CMS collaborations have observed this in ultraperipheral lead-to-lead collisions.
Now, CMS physicists report: first observation The same process occurs during proton-proton collisions.
These collisions provide greater sensitivity to physics over the standard model, as new physical effects increase with collision energy.
Taking advantage of the superior tracking capabilities of the CMS detector, the collaboration will isolate this particular process from other processes by selecting events that produce a tau with no other tracking within a distance of just 1 mm. I was able to separate it.
“This remarkable achievement in detecting proton-proton collisions in the super-periphery sets the stage for many breakthrough measurements of this kind from CMS experiments,” said Dr. Michael Pitt, a member of the CMS team. said.
This new method provided a new way to constrain tau's anomalous magnetic moments, and the CMS Collaboration quickly put it to the test.
Future driving data will likely improve the significance, but their new measurements impose the tightest constraints to date, with greater precision than ever before.
This reduces the prediction uncertainty to just three times the size of the quantum correction.
“We're really excited to finally be able to narrow down some of the fundamental properties of the elusive tau lepton,” said CMS team member Dr. Isaac Neutelings.
“This analysis introduces a new approach to investigating tau g-2 and revitalizes a measurement that has been stagnant for more than 20 years,” said CMS team member Dr. Xuelong Qin.
Two spiral galaxies, NGC 6040 and NGC 6039, have merged on the right side of this Hubble image. NGC 6039 is circular when viewed from the front. NGC 6040 appears to be before the first one. In the lower left corner of the frame, elliptical galaxy NGC 6041, the central member of the galaxy cluster in which Arp 122 resides, is visible as light emanating from a point. This color image was created in both the visible and infrared regions of the spectrum using Hubble's Altitude Survey Camera (ACS) and the Dark Energy Camera mounted on NSF's Victor M. Blanco 4-meter Telescope at Cerro Tololo Inter. Created from separate exposures taken in the area. -American Observatory of Chile. Four filters were used to sample different wavelengths. Color is obtained by assigning different hues to each monochromatic image associated with an individual filter. Image credits: NASA / ESA / Hubble / J. Dalcanton / Dark Energy Survey / DOE / FNAL / DECam / CTIO / NOIRLab / NSF / AURA / L. Shatz.
Alp 122 It is located in the constellation Hercules, approximately 570 million light years from Earth.
This system consists of two galaxies: a tilted and distorted spiral galaxy; NGC6040 and the spiral galaxy in front of me NGC6039.
“Galaxy collisions and mergers are highly energetic and dramatic events, but they occur on very slow timescales,” Hubble astronomers said in a statement.
“For example, our Milky Way galaxy is on a colliding orbit with its nearest galactic neighbor, the Andromeda galaxy, but it will still be four billion years before these two galaxies actually meet. ”
“The process of collision and fusion will not end soon either; it may take hundreds of millions of years to unfold.”
“These collisions take a very long time because they have very long distances.”
“Galaxies are composed of stars and their solar systems, dust and gas,” the researchers added.
“Over time, the structures of two (or more) colliding galaxies may change completely, eventually forming a single, merged galaxy.”
“That could be the result of the collision seen in this image.”
“Galaxies resulting from mergers are thought to have regular or elliptical structures because the merger process destroys more complex structures (such as those observed in spiral galaxies).”
“It will be interesting to see what Arp 122 will look like once this collision is complete, but that won't happen for a long time.”
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