Fixing a problem inside one of the world's most sophisticated scientific observatories might seem like the kind of challenge that demands a multimillion-dollar upgrade or revolutionary new technology.

But for scientists working on the Laser Interferometer Gravitational-Wave Observatory (LIGO), which listens for ripples in spacetime generated by cosmic collisions like merging black holes, the solution to a mild but persistent engineering challenge turns out to be as simple as an off-the-shelf camera.

By pairing commercially available thermal imaging cameras with computer models, a team led by Jonathan Richardson at the University of California, Riverside, has developed a technique that corrects tiny, heat-induced distortions in the observatory's mirrors — an elusive flaw that scientists say currently limits how far into deep space the facility can look.

"It doesn't require any new technology development, which is almost unheard of for solving a LIGO instrumentation problem," Richardson said in a statement.

Once incorporated into LIGO's upcoming upgrade, Richardson and his team estimate the fix would extend the observatory's reach by roughly 33 million light-years.

That gain might sound like a drop in the ocean against the unimaginably vast scale of the universe, but because space expands in three dimensions, pushing a detector's reach even slightly opens up an exponentially larger window of space. Being able to look further into the universe will allow astronomers to "hear" many more cosmic ripples, in turn increasing the potential for discovering the universe’s most violent collisions that lie beyond LIGO's reach today.

LIGO detects these cosmic ripples, known as gravitational waves, using twin L-shaped facilities in the U.S. — in the states of Washington and Louisiana. Inside each detector, a laser beam shoots down two 2.5-mile-long (4-kilometer-long) tunnels, bouncing off pristine mirrors at each end. When a gravitational wave passes through Earth, it subtly stretches one tunnel and squeezes the other. That microscopic shift alters the laser beams ever so slightly, producing a tiny flicker of light that alerts scientists to a distant cosmic event.

Because these cosmic signals are inconceivably small, preserving every single photon is crucial. To accomplish this, LIGO relies on mirrors polished to reflect 99.9999%t of the laser light that strikes them, ranking them among the purest optical components ever built.

Yet even these near-perfect mirrors have had one unavoidable flaw. The mirrors still absorb a tiny fraction of that intense laser light. That energy turns into heat, warping the mirror's surface by just a few nanometers, enough to distort the laser beam and reduce the observatory's overall sensitivity.

Physicists already knew they could counteract these distortions by applying targeted heat to the back of the mirrors. The difficult part was measuring the distortions accurately enough such that the correcting heat could be applied with exact precision.

The new technique uses infrared thermal images and existing computer models to reconstruct a map of distortions across the mirror's surface.

"You can think of it like taking an infrared picture of a car engine," Richardson said in the statement. "An engineer can look at the temperature pattern on the outside and infer what's happening inside the engine. We're doing the same thing with LIGO's mirrors."

And the technique isn't just a fix for LIGO. It is also expected to become part of the foundational design for Cosmic Explorer, a proposed next-generation U.S. gravitational-wave observatory targeted for the mid-2030s.

With 25-mile-long (40-km-long) arms — 10 times larger than LIGO's — Cosmic Explorer is already designed to detect gravitational wave events far beyond the reach of today's observatories. This new technique will only supercharge its ultimate reach.

"The goal for the next generation of gravitational-wave detectors is to achieve about 10 times the sensitivity of today's instruments," Richardson said in the statement. "One of the key obstacles to achieving that is reducing the fundamental quantum mechanical noise that limits the precision of the measurements."

The technique is described in a paper published July 16 in Classical and Quantum Gravity.

The launch of NASA's next super telescope, the Nancy Grace Roman Space Telescope (Roman), may mean there is nowhere left for violent black holes to hide.

In fact, these cosmic cannibals may not even be able to hide from Roman at "cosmic noon," a period of the universe's history that occurred around 11 billion to 12 billion years ago. The study of these gory stellar events so early in the history of the universe could help reveal how supermassive black holes grew so big, so rapidly.

Occurrences of black holes ripping apart stars are called tidal disruption events (TDEs), and they happen when an unfortunate star's orbit brings it too close to the immense gravitational influence of a supermassive black hole. This simultaneously squashes and squeezes the star in a process called "spaghettification," with plasma pasta wrapping around the black hole and being fed gradually to it.

Because supermassive black holes are wrapped in a one-way, light-trapping boundary called an event horizon, the only way to study them is when they are actively consuming surrounding matter. Such matter swirls around them in what are known as accretion disks.

However, lighter supermassive black holes aren't ravenous feeders, making them harder to investigate. That is, until a star gets too close and is shredded in an incredibly bright TDE that can outshine the combined light of every star in the supermassive black hole's host galaxy. TDEs are more common to supermassive black holes with masses of about 100,000 to 100 million suns, because supermassive black holes with masses over 1 billion solar masses tend to immediately swallow their stellar snacks.

Previous research has suggested TDEs wouldn't be common in the early universe, because the first supermassive black holes wouldn't even have a mass of 100,000 times that of the sun and thus wouldn't shred stars. However, a new study has reassessed the frequency of TDEs around 1 billion to 2 billion years after the Big Bang, finding they could be more common than previously estimated. Especially during the crowded conditions found during cosmic noon.

Set to launch on Aug. 30, 2026, scientists are hoping Roman's High-Latitude Time-Domain Survey, which will repeatedly revisit a region of the sky equivalent to 90 full moons, will be a powerful tool in the hunt for TDEs in the early universe and their subsequent study. This team estimated that Rubin will detect thousands to tens of thousands of TDEs each year, with 100s dating back to cosmic noon.

"The Roman Space Telescope is going to be transformative for transient science [transients are astronomical events that light up the sky then fade away]," research team leader Mitchell Karmen of the Johns Hopkins University said in a statement. "Thanks to Roman's high sensitivity, we can find multiple tidal disruption events out to greater distances and earlier cosmic times than ever before."

This means Roman is ideally poised to solve a puzzle that has developed since its predecessor, the James Webb Space Telescope (JWST), began beaming data back to Earth in July 2022.

How could early TDEs solve the puzzle of black hole growth

Supermassive black holes with masses equivalent to millions or even billions of suns are found at the hearts of all large galaxies. When they are seen in the relatively local universe, that isn't so problematic; they have had plenty of time to grow via mergers and feeding.

However, the JWST has been routinely spotting supermassive black holes prior to the universe being even 1 billion years old. That is troubling because these early black holes should have had to undergo at least 1 billion years of mergers and gluttonous feeding to reach supermassive status. Scientists have two prevailing theories as to how this growth may have happened.

The first suggests supermassive black holes grow from "light seeds," beginning with black holes with masses just a few hundred times that of the sun that are born from the death and collapse of massive stars.

Such black holes might weigh up to a few hundred times the mass of the sun. These black holes would then merge over time, as well as consume surrounding gas at an incredible rate that facilitates rapid growth. For this theory to be the right one, every young galaxy would have to harbor a massive black hole at its center.

The second theory suggests early supermassive black holes grew from "heavy seeds" created directly from the collapse of vast clouds of primordial gas and dust. This would allow rapid growth because black holes could begin the whole merger and feeding process before the first stars lived and died.

Should this be the correct pathway, however, the fact that collapse events would be rare would make massive black holes at the heart of cosmic noon galaxies less common.

Because TDEs are common to less massive supermassive black holes, counting their occurrence at cosmic noon could give an indication of the masses of black holes during that epoch — the key to determining between heavy seeds and light seeds.

"Tidal disruption events help us probe the population of light supermassive black holes, which can help us discriminate between these models," Karmen said.

"Just by counting the number of TDEs as a function of redshift [a measure of cosmic distance], you can put meaningful constraints on the population of million-solar-mass black holes. Roman will be transformative in that it can probe tidal disruption events out to greater distances, so you can look at how the rate of TDEs evolves over time," team member Suvi Gezari, an associate professor of astronomy at the University of Maryland, said. “Just like the JWST has transformed our understanding of distant, high-redshift [very distant] galaxies, Roman is poised to transform our understanding of high-redshift transients."

The team's research was published on July 14 in The Astrophysical Journal.

There may be an easier way to describe how black holes "leak" energy than the theory Stephen Hawking proposed — and the newly suggested process is similar to how we describe a boiling pot of water. This simple (well, relatively simple) description could be used to model black holes in many situations such as during their formation, mergers with other black holes, eventual evaporation and even explosive death.

In the 1970s, legendary theoretical physicist Stephen Hawking wrote a letter to the journal Nature entitled "Black hole explosions?" explaining how these objects may leak thermal radiation, evaporate and eventually implode at the end of their lives. This radiation eventually became known as Hawking radiation.

But in new research, scientists have suggested an alternative to Hawking radiation. It involves describing the increase in disorder, or entropy, of black holes. Boiling water, as an example, is also often described based on its increase in entropy. For black holes, this measure of entropy is connected to characteristics like spin and energy, which means it could be used to understand how these cosmic titans respond to different events.

"Hawking's laws of black hole mechanics provided a satisfying connection between extreme and ordinary physics and have been the paradigm for 50 years, but they have a serious limitation," team leader Abhay Ashtekar of the Eberly College of Science at Penn State University said in a statement. "They were formulated for black holes at equilibrium — or unchanging over time — but black holes are constantly changing; they form, merge, and eventually evaporate. We wanted to find a way to overcome this limitation and extend the laws to black holes that are out of equilibrium."

Black holes, Einstein and Hawking

To investigate the origins of black holes, one has to go back to history's most famous physicist (sorry Hawking, you're number two), Albert Einstein.

In 1915, Einstein revealed his theory of gravity, general relativity. One consequence of the equations underpinning that theory was the possibility of a singularity, a point at which the equations of general relativity go to infinity. This represents the heart of a black hole.

Another consequence of the general relativity equations is a region of space around this singularity at which gravity is so extreme that the escape velocity of the area increases to a value greater than the speed of light. That region is the light-trapping outer boundary of the black hole known as the event horizon, which prevents us from ever seeing the singularity at the heart of the black hole or receiving information from it. In fact, until Hawking's work in 1974, this is why it was proposed that nothing at all can escape a black hole.

"The laws of black hole mechanics came directly from Einstein's equations," team member Daniel E. Paraizo, a graduate student in physics at Penn State, said. "Because you cannot see into a black hole, it seemed that there could be an infinite number of ways to make a black hole, making their entropy infinite as well. They were also thought to only absorb energy and never radiate, so their temperature was zero."

However, the advent of Hawking radiation somewhat changed this paradigm. By suggesting that black holes actually radiate thermal energy, Hawking redefined them in such a way that suddenly the laws of thermodynamics could be applied to black holes.

"This changed the thinking about the thermodynamic properties of black holes from a sort of mathematical concept described by equations, to being more of a physical reality," Paraizo said. "This opened the door to finding analogies in black holes of entropy and temperature used in thermodynamics."

In Hawking's recipe for black holes, the area of the event horizon is proportional to its temperature and entropy, and is inversely proportional to its mass and its spin.

"There is a problem, though," team member Jonathan Shu, also from Penn State, said in the statement. "These analogies only really work for a black hole that is at equilibrium. In dynamic situations, event horizons can form and grow in what we call flat regions of space-time, where nothing is happening."

Shu added that a consequence of this is the properties of black holes cannot be determined just by the local physics of the black hole. Instead, determining the properties of black holes relies on the prediction of events that may or may not happen in the future.

"Therefore, the area of event horizons cannot be a measure of the physical entropy of dynamical black holes," Shu argues. "If we want to understand black holes that are growing, evaporating and merging, we need a viable alternative."

For the team, this meant replacing the event horizon of a black hole with something they call a "dynamical horizon," already used when scientists simulate black holes. Now, the first law of thermodynamics — which states the energy of a closed system cannot be created or destroyed but rather can only change forms — can be applied to black holes even when they are involved in dynamic acts. It also means black holes are subject to the second law of thermodynamics, which says the total entropy of an isolated system will always increase over time, during their birth, merger and death.

"This allows us to extend the first and second laws of thermodynamics to black holes that are not at equilibrium, thereby overcoming the limitations of the paradigm that has been used for over half a century," Ashtekar said. "We can apply these generalized laws to better understand evaporating black holes in quantum theory and black hole mergers."

The team's research was published in June in the journal Physical Review Letters.

The first of 10,000 missing black holes in the Omega Centauri globular cluster has been found thanks to teamwork by the Hubble and James Webb space telescopes.

The two observatories discovered the black hole after watching a star orbiting around something massive but dark, and which therefore could not be seen. The Hubble data ran from 2003 to 2023, and the James Webb Space Telescope picked up after that to help refine the measurements.

Astronomers used the space telescopes to focus on a particular star in a binary system that appeared to be home to another, dark object called oMEGACat BH-2. Previous studies had suggested that the dark object was a neutron star. However, the new results are conclusive: the object has a mass 4.46 times that of the sun. This is too massive to be a neutron star, so it must therefore be a black hole.

Omega Centauri is the most massive of our Milky Way galaxy's globular clusters. It is so massive that astronomers suspect that it is actually the core of a dwarf galaxy that has lost most of its stars to the Milky Way's gravitational cannibalism, which over the aeons has torn strips from Omega Centauri. Even so, Omega Centauri still contains about 10 million stars, collectively located 18,000 light-years from Earth.

In 2024, astronomers using the Hubble Space Telescope found clinching evidence that an intermediate-mass black hole – one that has a mass about 8,200 times that of our sun – lurks at the center of Omega Centauri, strengthening its claim of being the remnant of a dwarf galaxy, since galaxies harbor black holes at their center but star clusters typically do not.

However, alongside this intermediate-mass black hole should be about 10,000 other stellar-mass black holes born from the supernova explosions of massive stars. Searches have focused on binary systems where a star orbits a compact object, but until now astronomers had drawn a blank.

Now, a team led by Matthew Whitaker of the University of Utah in Salt Lake City have come along to save the day by diligently sifting through 20 years of Hubble observations, plus additional supporting views from the JWST, to uncover a stellar-mass black hole in Omega Centauri for the first time.

Whitaker's team used a technique called astrometry, which is the measurement of the changing positions of stars as they move through space. Although the black hole itself is dark, it is orbited by a normal star with a mass 78% that of our sun. Thanks to the unprecedented vision of Hubble and the JWST, Whitaker and his colleagues were able to track the motion of this star around the black hole.

It turns out that the star is on a 94-year-long orbit around the black hole, which is the widest separation of a binary composed of a stellar-mass black hole and star ever found. Over that 20-year-period, Hubble saw less than a quarter of the star's total orbit, but it coincided with the star's closest approach to the black hole, during which the star moved faster.

Based on this motion, Whitaker's team were able to measure the strength of the black hole's gravitational field acting on the star, and from that calculate the mass of the black hole.

"The precision of these measurements is incredible, down to a fraction of a pixel on Hubble and Webb's detectors," said Whitaker in a statement. "It would not have been possible to find this black hole without these two space telescopes."

Given how wide the orbit of the star is around the black hole, the likelihood is that the black hole's gravity captured the star when it passed close. This is a state of affairs that will not last forever; within another billion years, encounters with other stars in the crowded environs of the cluster will probably pluck the black hole's companion away.

The mass of oMEGACat BH-2 does seem unusual, however, in the sense that it is lower than expected. The mass of oMEGACat BH-2 exists in a void that has only become apparent during the past eleven years of gravitational wave detections. These gravitational waves are produced by the mergers of stellar-mass black holes, but black holes with masses between 2.5 times the mass of our sun (the theoretical limit for neutron stars) and five solar masses are conspicuous by their absence in the gravitational-wave events. Yet here is oMEGACat BH-2, sitting within that mass gap.

"It's important to understand black hole populations in globular clusters because there's uncertainty about their physics and formation," said Anil Seth of the University of Utah.

"More specifically, understanding the process of forming black holes and then dynamically forming binaries is vital, because it affects our ability to interpret and understand gravitational-wave events. Environments like Omega Centauri are the primary places where we think binaries are merging and creating these waves."

In particular, the stars of Omega Centauri are more primitive than our sun, chemically speaking, with fewer elements heavier than hydrogen and helium. Which types of massive stars produce black holes when they explode as supernovas is still an area of active research, but oMEGACat BH-2 adds another complication to the mix in that its progenitor star contained few heavy elements.

"We need to figure out how that happens," said Seth.

So that's one down, and 9,999 or thereabouts to go. Whitaker's team continue to use Hubble and JWST data to find more stellar-mass black holes in Omega Centauri, but he also highlights the potential of NASA's Nancy Grace Roman Space Telescope to find black-hole binary systems in our Milky Way galaxy at least when the telescope launches later this year.

"Roman … will image the crowded galactic bulge, including the galactic center, very regularly with Hubble-like resolution and with a much wider field of view," said Whitaker. "We're hoping we'll be able to find black hole binary systems like this one because of the regular cadence of Roman's observations."

The details regarding oMEGACat BH-2 are described in a paper published on July 13 in The Astrophysical Journal Letters.

A supermassive black hole at the heart of a nearby galaxy is behaving similarly to black holes that existed just after the Big Bang, voraciously feeding on copious amounts of matter. The relatively close cosmic titan could therefore provide insight into the much more distant universe.

Indeed, the intense accretion behavior demonstrated by the supermassive black hole, which sits at the center of the galaxy SDSS J110546.07+145202.4 located 1.8 billion light-years away, is something scientists have only ever seen in the earliest supermassive black holes.

SDSS J110546.07+145202.4 has been shining brightly in radio waves for many years, and these waves were the smoking gun that pointed to the feeding habits of the galaxy's central black hole.

"Such high-energy events can provide astronomers with a wealth of insights," Kovi Rose from the University of Sydney’s Sydney Institute for Astronomy said in the statement. "By observing these jets and outbursts, we can study the physical processes in some of the most extreme environments in the universe."

Even the hungriest black holes are messy eaters

All large galaxies have a supermassive black hole at their heart with masses of millions or even billions of times that of the sun. However, not all supermassive black holes accrete vast amounts of matter.

For example, the supermassive black hole at the heart of our galaxy, the Milky Way, Sagittarius A*, consumes so little gas and dust from its surroundings that, were it a human being, it would be existing on a diet of one grain of rice every million years. (That is one heck of a diet.)

When black holes are surrounded by copious amounts of gas and dust, their immense gravitational influence causes this material, in a flattened swirling cloud called an accretion disk, to glow brightly across the electromagnetic spectrum, from low-energy radio waves to high-energy X-rays.

Additionally, supermassive black holes are notoriously messy eaters, meaning some of the matter in accretion disks is channeled to the poles of the black hole, from where it is blasted out as jets of plasma traveling at speeds approaching the speed of light. These jets too are responsible for bright emissions of electromagnetic radiation.

Radio signals from the spiral galaxy SDSS J110546.07+145202.4 underwent a 20-fold increase in radio brightness over a short period, increasing to around 10 quadrillion times the intensity of the radio brightness of the sun. This happened around 8 years ago, and the galaxy has yet to show any sign of dimming.

"We are dealing with the prototype of a new class of galaxies that undergo rapid changes in radio emission," team member Phil Edwards from CSIRO, Australia’s national science agency, said.

Team leader Stefanie Komossa of the Max-Planck-Institute for Extraterrestrial Physics in Garching, Germany, added: "Luminous radio radiation from rapidly growing, lightweight black holes is rare to begin with. Their transition into a long-lasting, radio-bright state has never been observed before."

The source of this electromagnetic radiation is situated at the heart of SDSS J110546.07+145202.4, right by its central supermassive black hole. The team thinks the brightening of this galaxy began because the rate of matter falling into its supermassive black hole had increased, triggering the generation of plasma jets.

The increase in mass consumption of the supermassive black hole is leading to a level of growth that hasn't been seen in black holes outside of the early universe before. That means that SDSS J110546.07+145202.4 and its feasting supermassive black hole are set to be prime targets for astronomical investigations for some time to come, especially as proxies for ravenous black holes and rapidly growing early galaxies.

"With sensitive facilities like the incoming SKA telescopes, we'll be able to identify similar radio transients in future sky surveys," Komossa said. "This is crucial for filling the gaps in our understanding of the early universe."

The team's research was published in May in The Astrophysical Journal.

The European Space Agency's (ESA) Euclid space telescope has spotted 31 previously unknown quasars dating to the universe's earliest chapter, including the two oldest ever found.

The discoveries, described July 6 in the journal Astronomy & Astrophysics, more than double the number of known quasars from that primordial era and could help astronomers unravel one of cosmology's biggest mysteries: how supermassive black holes grew so enormous so quickly after the Big Bang.

"It's a big step towards understanding these fascinating objects on a more fundamental level," Antonio La Marca, an ESA research fellow on the Euclid team, said in a statement.

Quasars are among the brightest objects in the universe. They form when gas and dust spiral into a galaxy's central supermassive black hole, heating up and releasing enormous amounts of energy that can outshine the galaxy itself. Each of the two most ancient quasars detected in the new study shone with the light of a trillion suns, according to the researchers.

Euclid spotted the quasars while surveying the distant universe. Twelve of them have redshifts of 7 or higher, meaning their light has traveled for more than 13 billion years and dates to the universe's first 770 million years. Two of the objects, with redshifts of 7.77 and 7.69, are the most ancient quasars ever identified, shining just 670 million years after the Big Bang, when the universe was only about 5% of its current age.

"These early quasars date back to the Universe's infancy," Daming Yang, an astronomer at Leiden University in the Netherlands and first author of the new study, said in the statement. "By finding and studying them, we can better understand how these enormous systems formed and grew so quickly — one of the greatest mysteries in astrophysics."

Finding quasars from the early universe has long been difficult because they are rare and incredibly distant. Until now, astronomers had identified only the brightest examples, making it difficult to understand the broader population during this early era. Euclid's wide-field survey is changing that by detecting fainter quasars across huge swaths of the sky.

The latest discoveries represent only a fraction of what the telescope is expected to find during its six-year mission, which will cover more than one-third of the total sky once complete. Mounted with a pair of instruments that see in visible and near-infrared light, Euclid is currently assembling the largest-ever 3D map of the universe. Scientists expect the survey to uncover hundreds of similarly ancient quasars, providing an unprecedented look at how the universe's earliest galaxies and supermassive black holes evolved.

Euclid has also taken some time to study the nearby universe, revealing more than 60 million individual stars packed into the Milky Way's center in a sparkling image released in late June.

Black hole quiz: How supermassive is your knowledge of the universe?

Scientists have found evidence that gravitational waves from a spectacular black hole collision carry signals from the very edge of the newly formed black hole. If confirmed by future observations, the discovery could provide an entirely new way to investigate what happens in the immediate vicinity of a black hole without ever observing it directly.

In a new study, the researchers analyzed an exceptionally strong gravitational wave event known as GW250114. They identified a "direct wave," a subtle feature of the total gravitational wave signal predicted by theory but never previously detected in real data. The signal appears to contain information from extremely close to the black hole's event horizon, the boundary beyond which nothing, not even light, can escape.

The findings, published June 24 in the journal Nature, suggest that gravitational wave observatories may eventually allow astronomers to probe regions that have remained inaccessible since black holes were first predicted by Albert Einstein's theory of general relativity.

Listening to the edge of a black hole

Although astronomers have photographed the glowing material surrounding some supermassive black holes and have detected dozens of black hole mergers through gravitational waves, the event horizon itself has remained frustratingly difficult to study.

Unlike ordinary light, gravitational waves are tiny ripples in space-time produced when massive objects accelerate. They pass almost undisturbed through the universe, carrying information about violent cosmic events that would otherwise remain hidden.

According to study co-author Sizheng Ma, a postdoctoral researcher at the Perimeter Institute for Theoretical Physics in Canada, the newly identified signal offers a rare glimpse of what happens immediately after two black holes collide.

"When two black holes merge, they violently shake space-time itself," Ma told Live Science. "For a brief moment, the region very close to the newly formed black hole's horizon is swept into a fast, fading swirl."

Ma explained that the direct wave is the portion of the gravitational wave signal produced near the horizon and carries the imprint of that motion outward through space.

"That is why it is so interesting," he said. "It may let us 'listen' to what happens near the horizon, a region we cannot see directly with light."

A remarkable black hole collision

The team focused on GW250114, a black hole merger detected on Jan. 14, 2025, by the two Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors in Hanford, Washington, and Livingston, Louisiana.

"Our earlier theoretical work predicted that black hole mergers should produce a direct-wave signal from the near-horizon region," Ma said. "The big question was whether this effect could actually be seen in real data."

GW250114 turned out to provide exactly the conditions needed to test that prediction.

"It was strong enough, clean enough, and close enough to the theoretical situation where this signal should be visible," he said.

To search for the elusive feature, the researchers first removed the best-understood part of the gravitational wave signal, which comes from the newly formed black hole settling down after the merger. Then, they examined the remaining data to determine whether it consisted only of detector noise or contained another physical signal.

"What we found was striking," Ma said. "The remaining signal followed the expected rhythm and fading pattern of a wave shaped by the region very close to the final black hole's horizon."

The team concluded that the leftover signal matches the behavior expected for a direct wave predicted by previous theoretical studies.

A new way to explore extreme gravity

The researchers stressed that their findings do not reveal what lies inside a black hole. Instead, they're providing a new observational tool for investigating the region immediately outside the event horizon.

"The gravitational wave data appear to carry an imprint from very close to the newly formed black hole's horizon — the famous point of no return," Ma said.

He explained that the measurements are consistent with space-time near the horizon being rapidly dragged around by the spinning black hole while the signal fades because of the intense gravitational field.

"For us, the exciting message is that gravitational waves may be giving us a new way to study the edge of a black hole using real observational data," Ma said.

Ma believes the method could eventually become useful for exploring ideas such as quantum gravity — which seeks to unite Einstein's theory of gravity with quantum mechanics — or the black hole information paradox, the longstanding puzzle of whether information that falls into a black hole is truly lost. However, it cannot test those questions directly yet.

"If quantum effects, or any deviations from the standard black-hole picture, leave a measurable imprint there, then direct waves could, in principle, help us search for them in the future," he said.

More observations will be needed

The researchers cautioned that the discovery is based on a single gravitational wave event. While GW250114 provided exceptionally favorable conditions, much stronger evidence will come only if similar signals are found in many additional black hole mergers.

"There are two main directions," Ma said. "The first is theory."

Current models capture the essential physics but remain simplified, and more realistic descriptions of black hole mergers will be needed.

"The second is observation," he added. "This result comes from one exceptionally loud and clean event, so the strongest confirmation would come from seeing the same kind of pattern in other black hole mergers."

As gravitational wave observatories continue to improve and detect increasing numbers of mergers, researchers hope to determine whether direct waves are a universal feature of black hole collisions.

"If the pattern appears repeatedly in the way general relativity predicts," Ma said, "direct waves could become a new way to study black hole horizons or the regions very close to them, and to test Einstein's theory in one of the most extreme environments in the universe."

If future observations confirm the team's results, scientists may have gained something they have sought for decades: a direct observational window into the very edge of a black hole.

See how much you know about black holes with our black hole quiz!