"Time and space are modes in which we think and not conditions in which we live."

— Albert Einstein

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Thousands of seadragons are dying in Australia's toxic algal bloom

New Scientist Space - Cosmology - Thu, 07/24/2025 - 11:00am
An algal bloom in South Australia has caused mass deaths of many species since March - now researchers warn that leafy and weedy seadragons could be facing the threat of extinction
Categories: Astronomy

Astronomers calculate that the universe will die in 33 billion years — much sooner than we thought

Space.com - Thu, 07/24/2025 - 11:00am
The theorists predict that the beginning of the end will be in about 10 billion years — less than the present age of the universe.
Categories: Astronomy

How NASA Is Testing AI to Make Earth-Observing Satellites Smarter

NASA News - Thu, 07/24/2025 - 10:59am

5 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater) Cloud cover can keep optical instruments on satellites from clearly capturing Earth’s surface. Still in testing, JPL’s Dynamic Targeting uses AI to avoid imaging clouds, yielding a higher proportion of usable data, and to focus on phenomena like this 2015 volcanic eruption in Indonesia Landsat 8 captured.NASA/USGS

A technology called Dynamic Targeting could enable spacecraft to decide, autonomously and within seconds, where to best make science observations from orbit.

In a recent test, NASA showed how artificial intelligence-based technology could help orbiting spacecraft provide more targeted and valuable science data. The technology enabled an Earth-observing satellite for the first time to look ahead along its orbital path, rapidly process and analyze imagery with onboard AI, and determine where to point an instrument. The whole process took less than 90 seconds, without any human involvement.

Called Dynamic Targeting, the concept has been in development for more than a decade at NASA’s Jet Propulsion Laboratory in Southern California. The first of a series of flight tests occurred aboard a commercial satellite in mid-July. The goal: to show the potential of Dynamic Targeting to enable orbiters to improve ground imaging by avoiding clouds and also to autonomously hunt for specific, short-lived phenomena like wildfires, volcanic eruptions, and rare storms.

This graphic shows how JPL’s Dynamic Targeting uses a lookahead sensor to see what’s on a satellite’s upcoming path. Onboard algorithms process the sensor’s data, identifying clouds to avoid and targets of interest for closer observation as the satellite passes overhead.NASA/JPL-Caltech

“The idea is to make the spacecraft act more like a human: Instead of just seeing data, it’s thinking about what the data shows and how to respond,” says Steve Chien, a technical fellow in AI at JPL and principal investigator for the Dynamic Targeting project. “When a human sees a picture of trees burning, they understand it may indicate a forest fire, not just a collection of red and orange pixels. We’re trying to make the spacecraft have the ability to say, ‘That’s a fire,’ and then focus its sensors on the fire.”

Avoiding Clouds for Better Science

This first flight test for Dynamic Targeting wasn’t hunting specific phenomena like fires — that will come later. Instead, the point was avoiding an omnipresent phenomenon: clouds.

Most science instruments on orbiting spacecraft look down at whatever is beneath them. However, for Earth-observing satellites with optical sensors, clouds can get in the way as much as two-thirds of the time, blocking views of the surface. To overcome this, Dynamic Targeting looks 300 miles (500 kilometers) ahead and has the ability to distinguish between clouds and clear sky. If the scene is clear, the spacecraft images the surface when passing overhead. If it’s cloudy, the spacecraft cancels the imaging activity to save data storage for another target.

“If you can be smart about what you’re taking pictures of, then you only image the ground and skip the clouds. That way, you’re not storing, processing, and downloading all this imagery researchers really can’t use,” said Ben Smith of JPL, an associate with NASA’s Earth Science Technology Office, which funds the Dynamic Targeting work. “This technology will help scientists get a much higher proportion of usable data.”

How Dynamic Targeting Works

The testing is taking place on CogniSAT-6, a briefcase-size CubeSat that launched in March 2024. The satellite — designed, built, and operated by Open Cosmos — hosts a payload designed and developed by Ubotica featuring a commercially available AI processor. While working with Ubotica in 2022, Chien’s team conducted tests aboard the International Space Station running algorithms similar to those in Dynamic Targeting on the same type of processor. The results showed the combination could work for space-based remote sensing.

Since CogniSAT-6 lacks an imager dedicated to looking ahead, the spacecraft tilts forward 40 to 50 degrees to point its optical sensor, a camera that sees both visible and near-infrared light. Once look-ahead imagery has been acquired, Dynamic Targeting’s advanced algorithm, trained to identify clouds, analyzes it. Based on that analysis, the Dynamic Targeting planning software determines where to point the sensor for cloud-free views. Meanwhile, the satellite tilts back toward nadir (looking directly below the spacecraft) and snaps the planned imagery, capturing only the ground.

This all takes place in 60 to 90 seconds, depending on the original look-ahead angle, as the spacecraft speeds in low Earth orbit at nearly 17,000 mph (7.5 kilometers per second).

What’s Next

With the cloud-avoidance capability now proven, the next test will be hunting for storms and severe weather — essentially targeting clouds instead of avoiding them. Another test will be to search for thermal anomalies like wildfires and volcanic eruptions. The JPL team developed unique algorithms for each application.

“This initial deployment of Dynamic Targeting is a hugely important step,” Chien said. “The end goal is operational use on a science mission, making for a very agile instrument taking novel measurements.”

There are multiple visions for how that could happen — possibly even on spacecraft exploring the solar system. In fact, Chien and his JPL colleagues drew some inspiration for their Dynamic Targeting work from another project they had also worked on: using data from ESA’s (the European Space Agency’s) Rosetta orbiter to demonstrate the feasibility of autonomously detecting and imaging plumes emitted by comet 67P/Churyumov-Gerasimenko.

On Earth, adapting Dynamic Targeting for use with radar could allow scientists to study dangerous extreme winter weather events called deep convective ice storms, which are too rare and short-lived to closely observe with existing technologies. Specialized algorithms would identify these dense storm formations with a satellite’s look-ahead instrument. Then a powerful, focused radar would pivot to keep the ice clouds in view, “staring” at them as the spacecraft speeds by overhead and gathers a bounty of data over six to eight minutes.

Some ideas involve using Dynamic Targeting on multiple spacecraft: The results of onboard image analysis from a leading satellite could be rapidly communicated to a trailing satellite, which could be tasked with targeting specific phenomena. The data could even be fed to a constellation of dozens of orbiting spacecraft. Chien is leading a test of that concept, called Federated Autonomous MEasurement, beginning later this year.

How AI supports Mars rover science Autonomous robot fleet could measure ice shelf melt Ocean world robot swarm prototype gets a swim test News Media Contact

Melissa Pamer
Jet Propulsion Laboratory, Pasadena, Calif.
626-314-4928
melissa.pamer@jpl.nasa.gov

2025-094

Share Details Last Updated Jul 24, 2025 Related Terms Explore More 5 min read NASA Shares How to Save Camera 370-Million-Miles Away Near Jupiter Article 3 days ago 2 min read GLOBE-Trotting Science Lands in Chesapeake with NASA eClips

On June 16-17, 2025, 50 students at Camp Young in Chesapeake, Virginia traded their usual…

Article 3 days ago
6 min read 5 Things to Know About Powerful New U.S.-India Satellite, NISAR Article 3 days ago Keep Exploring Discover Related Topics

Missions

Humans in Space

Climate Change

Solar System

Categories: NASA

How NASA Is Testing AI to Make Earth-Observing Satellites Smarter

NASA - Breaking News - Thu, 07/24/2025 - 10:59am

5 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater) Cloud cover can keep optical instruments on satellites from clearly capturing Earth’s surface. Still in testing, JPL’s Dynamic Targeting uses AI to avoid imaging clouds, yielding a higher proportion of usable data, and to focus on phenomena like this 2015 volcanic eruption in Indonesia Landsat 8 captured.NASA/USGS

A technology called Dynamic Targeting could enable spacecraft to decide, autonomously and within seconds, where to best make science observations from orbit.

In a recent test, NASA showed how artificial intelligence-based technology could help orbiting spacecraft provide more targeted and valuable science data. The technology enabled an Earth-observing satellite for the first time to look ahead along its orbital path, rapidly process and analyze imagery with onboard AI, and determine where to point an instrument. The whole process took less than 90 seconds, without any human involvement.

Called Dynamic Targeting, the concept has been in development for more than a decade at NASA’s Jet Propulsion Laboratory in Southern California. The first of a series of flight tests occurred aboard a commercial satellite in mid-July. The goal: to show the potential of Dynamic Targeting to enable orbiters to improve ground imaging by avoiding clouds and also to autonomously hunt for specific, short-lived phenomena like wildfires, volcanic eruptions, and rare storms.

This graphic shows how JPL’s Dynamic Targeting uses a lookahead sensor to see what’s on a satellite’s upcoming path. Onboard algorithms process the sensor’s data, identifying clouds to avoid and targets of interest for closer observation as the satellite passes overhead.NASA/JPL-Caltech

“The idea is to make the spacecraft act more like a human: Instead of just seeing data, it’s thinking about what the data shows and how to respond,” says Steve Chien, a technical fellow in AI at JPL and principal investigator for the Dynamic Targeting project. “When a human sees a picture of trees burning, they understand it may indicate a forest fire, not just a collection of red and orange pixels. We’re trying to make the spacecraft have the ability to say, ‘That’s a fire,’ and then focus its sensors on the fire.”

Avoiding Clouds for Better Science

This first flight test for Dynamic Targeting wasn’t hunting specific phenomena like fires — that will come later. Instead, the point was avoiding an omnipresent phenomenon: clouds.

Most science instruments on orbiting spacecraft look down at whatever is beneath them. However, for Earth-observing satellites with optical sensors, clouds can get in the way as much as two-thirds of the time, blocking views of the surface. To overcome this, Dynamic Targeting looks 300 miles (500 kilometers) ahead and has the ability to distinguish between clouds and clear sky. If the scene is clear, the spacecraft images the surface when passing overhead. If it’s cloudy, the spacecraft cancels the imaging activity to save data storage for another target.

“If you can be smart about what you’re taking pictures of, then you only image the ground and skip the clouds. That way, you’re not storing, processing, and downloading all this imagery researchers really can’t use,” said Ben Smith of JPL, an associate with NASA’s Earth Science Technology Office, which funds the Dynamic Targeting work. “This technology will help scientists get a much higher proportion of usable data.”

How Dynamic Targeting Works

The testing is taking place on CogniSAT-6, a briefcase-size CubeSat that launched in March 2024. The satellite — designed, built, and operated by Open Cosmos — hosts a payload designed and developed by Ubotica featuring a commercially available AI processor. While working with Ubotica in 2022, Chien’s team conducted tests aboard the International Space Station running algorithms similar to those in Dynamic Targeting on the same type of processor. The results showed the combination could work for space-based remote sensing.

Since CogniSAT-6 lacks an imager dedicated to looking ahead, the spacecraft tilts forward 40 to 50 degrees to point its optical sensor, a camera that sees both visible and near-infrared light. Once look-ahead imagery has been acquired, Dynamic Targeting’s advanced algorithm, trained to identify clouds, analyzes it. Based on that analysis, the Dynamic Targeting planning software determines where to point the sensor for cloud-free views. Meanwhile, the satellite tilts back toward nadir (looking directly below the spacecraft) and snaps the planned imagery, capturing only the ground.

This all takes place in 60 to 90 seconds, depending on the original look-ahead angle, as the spacecraft speeds in low Earth orbit at nearly 17,000 mph (7.5 kilometers per second).

What’s Next

With the cloud-avoidance capability now proven, the next test will be hunting for storms and severe weather — essentially targeting clouds instead of avoiding them. Another test will be to search for thermal anomalies like wildfires and volcanic eruptions. The JPL team developed unique algorithms for each application.

“This initial deployment of Dynamic Targeting is a hugely important step,” Chien said. “The end goal is operational use on a science mission, making for a very agile instrument taking novel measurements.”

There are multiple visions for how that could happen — possibly even on spacecraft exploring the solar system. In fact, Chien and his JPL colleagues drew some inspiration for their Dynamic Targeting work from another project they had also worked on: using data from ESA’s (the European Space Agency’s) Rosetta orbiter to demonstrate the feasibility of autonomously detecting and imaging plumes emitted by comet 67P/Churyumov-Gerasimenko.

On Earth, adapting Dynamic Targeting for use with radar could allow scientists to study dangerous extreme winter weather events called deep convective ice storms, which are too rare and short-lived to closely observe with existing technologies. Specialized algorithms would identify these dense storm formations with a satellite’s look-ahead instrument. Then a powerful, focused radar would pivot to keep the ice clouds in view, “staring” at them as the spacecraft speeds by overhead and gathers a bounty of data over six to eight minutes.

Some ideas involve using Dynamic Targeting on multiple spacecraft: The results of onboard image analysis from a leading satellite could be rapidly communicated to a trailing satellite, which could be tasked with targeting specific phenomena. The data could even be fed to a constellation of dozens of orbiting spacecraft. Chien is leading a test of that concept, called Federated Autonomous MEasurement, beginning later this year.

How AI supports Mars rover science Autonomous robot fleet could measure ice shelf melt Ocean world robot swarm prototype gets a swim test News Media Contact

Melissa Pamer
Jet Propulsion Laboratory, Pasadena, Calif.
626-314-4928
melissa.pamer@jpl.nasa.gov

2025-094

Share Details Last Updated Jul 24, 2025 Related Terms Explore More 5 min read NASA Shares How to Save Camera 370-Million-Miles Away Near Jupiter Article 4 days ago 2 min read GLOBE-Trotting Science Lands in Chesapeake with NASA eClips

On June 16-17, 2025, 50 students at Camp Young in Chesapeake, Virginia traded their usual…

Article 4 days ago
6 min read 5 Things to Know About Powerful New U.S.-India Satellite, NISAR Article 4 days ago Keep Exploring Discover Related Topics

Missions

Humans in Space

Climate Change

Solar System

Categories: NASA

NASA’s Hubble, Chandra Spot Rare Type of Black Hole Eating a Star

NASA News - Thu, 07/24/2025 - 10:00am
Explore Hubble

6 Min Read NASA’s Hubble, Chandra Spot Rare Type of Black Hole Eating a Star

NASA’s Hubble Space Telescope and NASA’s Chandra X-ray Observatory team up to identify a possible intermediate-mass black hole.

Credits:
NASA, ESA, CXC, Yi-Chi Chang (National Tsing Hua University); Image Processing: Joseph DePasquale (STScI)

NASA’s Hubble Space Telescope and NASA’s Chandra X-ray Observatory have teamed up to identify a new possible example of a rare class of black holes. Called NGC 6099 HLX-1, this bright X-ray source seems to reside in a compact star cluster in a giant elliptical galaxy.

Just a few years after its 1990 launch, Hubble discovered that galaxies throughout the universe can contain supermassive black holes at their centers weighing millions or billions of times the mass of our Sun. In addition, galaxies also contain as many as millions of small black holes weighing less than 100 times the mass of the Sun. These form when massive stars reach the end of their lives.

Far more elusive are intermediate-mass black holes (IMBHs), weighing between a few hundred to a few 100,000 times the mass of our Sun. This not-too-big, not-too-small category of black holes is often invisible to us because IMBHs don’t gobble as much gas and stars as the supermassive ones, which would emit powerful radiation. They have to be caught in the act of foraging in order to be found. When they occasionally devour a hapless bypassing star — in what astronomers call a tidal disruption event— they pour out a gusher of radiation.

The newest probable IMBH, caught snacking in telescope data, is located on the galaxy NGC 6099’s outskirts at approximately 40,000 light-years from the galaxy’s center, as described in a new study in the Astrophysical Journal. The galaxy is located about 450 million light-years away in the constellation Hercules.

A Hubble Space Telescope image of a pair of galaxies: NGC 6099 (lower left) and NGC 6098 (upper right). The purple blob depicts X-ray emission from a compact star cluster. The X-rays are produced by an intermediate-mass black hole tearing apart a star. Science: NASA, ESA, CXC, Yi-Chi Chang (National Tsing Hua University); Image Processing: Joseph DePasquale (STScI)

Astronomers first saw an unusual source of X-rays in an image taken by Chandra in 2009. They then followed its evolution with ESA’s XMM-Newton space observatory.

“X-ray sources with such extreme luminosity are rare outside galaxy nuclei and can serve as a key probe for identifying elusive IMBHs. They represent a crucial missing link in black hole evolution between stellar mass and supermassive black holes,” said lead author Yi-Chi Chang of the National Tsing Hua University, Hsinchu, Taiwan.

X-ray emission coming from NGC 6099 HLX-1 has a temperature of 3 million degrees, consistent with a tidal disruption event. Hubble found evidence for a small cluster of stars around the black hole. This cluster would give the black hole a lot to feast on, because the stars are so closely crammed together that they are just a few light-months apart (about 500 billion miles).

The suspected IMBH reached maximum brightness in 2012 and then continued declining to 2023. The optical and X-ray observations over the period do not overlap, so this complicates the interpretation. The black hole may have ripped apart a captured star, creating a plasma disk that displays variability, or it may have formed a disk that flickers as gas plummets toward the black hole.

“If the IMBH is eating a star, how long does it take to swallow the star’s gas? In 2009, HLX-1 was fairly bright. Then in 2012, it was about 100 times brighter. And then it went down again,” said study co-author Roberto Soria of the Italian National Institute for Astrophysics (INAF). “So now we need to wait and see if it’s flaring multiple times, or there was a beginning, there was peak, and now it’s just going to go down all the way until it disappears.”

The IMBH is on the outskirts of the host galaxy, NGC 6099, about 40,000 light-years from the galaxy’s center. There is presumably a supermassive black hole at the galaxy’s core, which is currently quiescent and not devouring a star.

Black Hole Building Blocks

The team emphasizes that doing a survey of IMBHs can reveal how the larger supermassive black holes form in the first place. There are two alternative theories. One is that IMBHs are the seeds for building up even larger black holes by coalescing together, since big galaxies grow by taking in smaller galaxies. The black hole in the middle of a galaxy grows as well during these mergers. Hubble observations uncovered a proportional relationship: the more massive the galaxy, the bigger the black hole. The emerging picture with this new discovery is that galaxies could have “satellite IMBHs” that orbit in a galaxy’s halo but don’t always fall to the center.

Another theory is that the gas clouds in the middle of dark-matter halos in the early universe don’t make stars first, but just collapse directly into a supermassive black hole. NASA’s James Webb Space Telescope’s discovery of very distant black holes being disproportionately more massive relative to their host galaxy tends to support this idea.

However, there could be an observational bias toward the detection of extremely massive black holes in the distant universe, because those of smaller size are too faint to be seen. In reality, there could be more variety out there in how our dynamic universe constructs black holes. Supermassive black holes collapsing inside dark-matter halos might simply grow in a different way from those living in dwarf galaxies where black-hole accretion might be the favored growth mechanism.

“So if we are lucky, we’re going to find more free-floating black holes suddenly becoming X-ray bright because of a tidal disruption event. If we can do a statistical study, this will tell us how many of these IMBHs there are, how often they disrupt a star, how bigger galaxies have grown by assembling smaller galaxies.” said Soria.

The challenge is that Chandra and XMM-Newton only look at a small fraction of the sky, so they don’t often find new tidal disruption events, in which black holes are consuming stars. The Vera C. Rubin Observatory in Chile, an all-sky survey telescope from the U.S. National Science Foundation and the Department of Energy, could detect these events in optical light as far as hundreds of millions of light-years away. Follow-up observations with Hubble and Webb can reveal the star cluster around the black hole.

The Hubble Space Telescope has been operating for more than three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.

Facebook logo @NASAHubble

@NASAHubble

Instagram logo @NASAHubble

Related Images & Videos

NGC 6099 (Hubble + Chandra)

A Hubble Space Telescope image of a pair of galaxies: NGC 6099 (lower left) and NGC 6098 (upper right). The purple blob depicts X-ray emission from a compact star cluster. The X-rays are produced by an intermediate-mass black hole tearing apart a star.



NGC 6099 (Hubble)

A Hubble Space Telescope image of a pair of galaxies: NGC 6099 (lower left) and NGC 6098 (upper right). The white dot labeled HLX-1 is the visible-light component of the location of a compact star cluster where an intermediate-mass black hole is tearing apart a star.



NGC 6099 Compass Image

This compass image shows two elliptical galaxies, NGC 6098 at upper right and NGC 6099 at lower left. The fuzzy purple blob at bottom center shows X-ray emission produced by an intermediate-mass black hole tearing apart a star. 



HLX-1 Illustration

This sequence of artistic illustrations, from upper left to bottom right, shows how a black hole in the core of a star cluster captures a bypassing star and gravitationally shreds it until there is an explosion, seen in the outskirts of the host galaxy.



HLX-1 Animation

This video is an illustration of an intermediate-mass black hole capturing and gravitationally shredding a star. It begins by zooming into a pair of galaxies. The galaxy at lower left, NGC 6099, contain a dense star cluster at center. The video then zooms into the heart of the cl…




Share

Details

Last Updated

Jul 24, 2025

Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Contact

Media

Claire Andreoli
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
claire.andreoli@nasa.gov

Ray Villard
Space Telescope Science Institute
Baltimore, Maryland

Related Terms

Related Links and Documents

Keep Exploring Discover More Topics From Hubble

Hubble Space Telescope

Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.


Reshaping Our Cosmic View: Hubble Science Highlights


Hubble Black Holes


Hubble Focus: Black Holes – Into the Vortex

Categories: NASA

NASA’s Hubble, Chandra Spot Rare Type of Black Hole Eating a Star

NASA - Breaking News - Thu, 07/24/2025 - 10:00am
Explore Hubble

6 Min Read NASA’s Hubble, Chandra Spot Rare Type of Black Hole Eating a Star

NASA’s Hubble Space Telescope and NASA’s Chandra X-ray Observatory team up to identify a possible intermediate-mass black hole.

Credits:
NASA, ESA, CXC, Yi-Chi Chang (National Tsing Hua University); Image Processing: Joseph DePasquale (STScI)

NASA’s Hubble Space Telescope and NASA’s Chandra X-ray Observatory have teamed up to identify a new possible example of a rare class of black holes. Called NGC 6099 HLX-1, this bright X-ray source seems to reside in a compact star cluster in a giant elliptical galaxy.

Just a few years after its 1990 launch, Hubble discovered that galaxies throughout the universe can contain supermassive black holes at their centers weighing millions or billions of times the mass of our Sun. In addition, galaxies also contain as many as millions of small black holes weighing less than 100 times the mass of the Sun. These form when massive stars reach the end of their lives.

Far more elusive are intermediate-mass black holes (IMBHs), weighing between a few hundred to a few 100,000 times the mass of our Sun. This not-too-big, not-too-small category of black holes is often invisible to us because IMBHs don’t gobble as much gas and stars as the supermassive ones, which would emit powerful radiation. They have to be caught in the act of foraging in order to be found. When they occasionally devour a hapless bypassing star — in what astronomers call a tidal disruption event— they pour out a gusher of radiation.

The newest probable IMBH, caught snacking in telescope data, is located on the galaxy NGC 6099’s outskirts at approximately 40,000 light-years from the galaxy’s center, as described in a new study in the Astrophysical Journal. The galaxy is located about 450 million light-years away in the constellation Hercules.

A Hubble Space Telescope image of a pair of galaxies: NGC 6099 (lower left) and NGC 6098 (upper right). The purple blob depicts X-ray emission from a compact star cluster. The X-rays are produced by an intermediate-mass black hole tearing apart a star. Science: NASA, ESA, CXC, Yi-Chi Chang (National Tsing Hua University); Image Processing: Joseph DePasquale (STScI)

Astronomers first saw an unusual source of X-rays in an image taken by Chandra in 2009. They then followed its evolution with ESA’s XMM-Newton space observatory.

“X-ray sources with such extreme luminosity are rare outside galaxy nuclei and can serve as a key probe for identifying elusive IMBHs. They represent a crucial missing link in black hole evolution between stellar mass and supermassive black holes,” said lead author Yi-Chi Chang of the National Tsing Hua University, Hsinchu, Taiwan.

X-ray emission coming from NGC 6099 HLX-1 has a temperature of 3 million degrees, consistent with a tidal disruption event. Hubble found evidence for a small cluster of stars around the black hole. This cluster would give the black hole a lot to feast on, because the stars are so closely crammed together that they are just a few light-months apart (about 500 billion miles).

The suspected IMBH reached maximum brightness in 2012 and then continued declining to 2023. The optical and X-ray observations over the period do not overlap, so this complicates the interpretation. The black hole may have ripped apart a captured star, creating a plasma disk that displays variability, or it may have formed a disk that flickers as gas plummets toward the black hole.

“If the IMBH is eating a star, how long does it take to swallow the star’s gas? In 2009, HLX-1 was fairly bright. Then in 2012, it was about 100 times brighter. And then it went down again,” said study co-author Roberto Soria of the Italian National Institute for Astrophysics (INAF). “So now we need to wait and see if it’s flaring multiple times, or there was a beginning, there was peak, and now it’s just going to go down all the way until it disappears.”

The IMBH is on the outskirts of the host galaxy, NGC 6099, about 40,000 light-years from the galaxy’s center. There is presumably a supermassive black hole at the galaxy’s core, which is currently quiescent and not devouring a star.

Black Hole Building Blocks

The team emphasizes that doing a survey of IMBHs can reveal how the larger supermassive black holes form in the first place. There are two alternative theories. One is that IMBHs are the seeds for building up even larger black holes by coalescing together, since big galaxies grow by taking in smaller galaxies. The black hole in the middle of a galaxy grows as well during these mergers. Hubble observations uncovered a proportional relationship: the more massive the galaxy, the bigger the black hole. The emerging picture with this new discovery is that galaxies could have “satellite IMBHs” that orbit in a galaxy’s halo but don’t always fall to the center.

Another theory is that the gas clouds in the middle of dark-matter halos in the early universe don’t make stars first, but just collapse directly into a supermassive black hole. NASA’s James Webb Space Telescope’s discovery of very distant black holes being disproportionately more massive relative to their host galaxy tends to support this idea.

However, there could be an observational bias toward the detection of extremely massive black holes in the distant universe, because those of smaller size are too faint to be seen. In reality, there could be more variety out there in how our dynamic universe constructs black holes. Supermassive black holes collapsing inside dark-matter halos might simply grow in a different way from those living in dwarf galaxies where black-hole accretion might be the favored growth mechanism.

“So if we are lucky, we’re going to find more free-floating black holes suddenly becoming X-ray bright because of a tidal disruption event. If we can do a statistical study, this will tell us how many of these IMBHs there are, how often they disrupt a star, how bigger galaxies have grown by assembling smaller galaxies.” said Soria.

The challenge is that Chandra and XMM-Newton only look at a small fraction of the sky, so they don’t often find new tidal disruption events, in which black holes are consuming stars. The Vera C. Rubin Observatory in Chile, an all-sky survey telescope from the U.S. National Science Foundation and the Department of Energy, could detect these events in optical light as far as hundreds of millions of light-years away. Follow-up observations with Hubble and Webb can reveal the star cluster around the black hole.

The Hubble Space Telescope has been operating for more than three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.

Facebook logo @NASAHubble

@NASAHubble

Instagram logo @NASAHubble

Related Images & Videos

NGC 6099 (Hubble + Chandra)

A Hubble Space Telescope image of a pair of galaxies: NGC 6099 (lower left) and NGC 6098 (upper right). The purple blob depicts X-ray emission from a compact star cluster. The X-rays are produced by an intermediate-mass black hole tearing apart a star.



NGC 6099 (Hubble)

A Hubble Space Telescope image of a pair of galaxies: NGC 6099 (lower left) and NGC 6098 (upper right). The white dot labeled HLX-1 is the visible-light component of the location of a compact star cluster where an intermediate-mass black hole is tearing apart a star.



NGC 6099 Compass Image

This compass image shows two elliptical galaxies, NGC 6098 at upper right and NGC 6099 at lower left. The fuzzy purple blob at bottom center shows X-ray emission produced by an intermediate-mass black hole tearing apart a star. 



HLX-1 Illustration

This sequence of artistic illustrations, from upper left to bottom right, shows how a black hole in the core of a star cluster captures a bypassing star and gravitationally shreds it until there is an explosion, seen in the outskirts of the host galaxy.



HLX-1 Animation

This video is an illustration of an intermediate-mass black hole capturing and gravitationally shredding a star. It begins by zooming into a pair of galaxies. The galaxy at lower left, NGC 6099, contain a dense star cluster at center. The video then zooms into the heart of the cl…




Share

Details

Last Updated

Jul 24, 2025

Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Contact

Media

Claire Andreoli
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
claire.andreoli@nasa.gov

Ray Villard
Space Telescope Science Institute
Baltimore, Maryland

Related Terms

Related Links and Documents

Keep Exploring Discover More Topics From Hubble

Hubble Space Telescope

Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.


Reshaping Our Cosmic View: Hubble Science Highlights


Hubble Black Holes


Hubble Focus: Black Holes – Into the Vortex

Categories: NASA

New moon of July 2025 sees Saturn swim with the fishes tonight

Space.com - Thu, 07/24/2025 - 10:00am
Saturn will be quite distinct in the Pisces constellation.
Categories: Astronomy

Gravitational Wave Science Faces Budget Cuts Just Years After Breakthrough Discoveries

Scientific American.com - Thu, 07/24/2025 - 10:00am

Less than a decade since the first detection of gravitational waves—ripples in spacetime itself—proposed budget cuts threaten to silence this groundbreaking science

Categories: Astronomy

Polymetallic Nodules, a Source of Rare Metals, May Hold the Secrets of 'Dark Oxygen'

Scientific American.com - Thu, 07/24/2025 - 10:00am

When researchers discovered "dark oxygen" last year, the news spread around the world, but the biggest challenge to the science comes from its funders.

Categories: Astronomy

Our brain's mitochondria may play a crucial role in the onset of sleep

New Scientist Space - Cosmology - Thu, 07/24/2025 - 9:00am
Textbooks say that mitochondria exist to supply cells with energy, but experiments in fruit flies suggest they are also involved in sleep
Categories: Astronomy

Our brain's mitochondria may play a crucial role in the onset of sleep

New Scientist Space - Space Headlines - Thu, 07/24/2025 - 9:00am
Textbooks say that mitochondria exist to supply cells with energy, but experiments in fruit flies suggest they are also involved in sleep
Categories: Astronomy

'Here today, Gorn tomorrow:' Showrunners talk putting a classic alien adversary to rest in 'Star Trek: Strange New Worlds' (exclusive)

Space.com - Thu, 07/24/2025 - 9:00am
'Here today, Gorn tomorrow. I think it's now time for other scary things to take their place.'
Categories: Astronomy

New fiber optic telescope 4MOST channels 'The Fantastic Four' | Space photo of the day for July 24, 2025

Space.com - Thu, 07/24/2025 - 8:00am
Marvel's new superhero movie isn't the only thing featuring some of the brightest stars.
Categories: Astronomy

Largest-ever supernova catalog ever provides further evidence dark energy is weakening

Space.com - Thu, 07/24/2025 - 6:00am
A catalog of over 2,000 exploding white dwarf vampire stars, the largest ever gathered, has provided further evidence that dark energy is weakening.
Categories: Astronomy

First MetOp Second Generation satellite fuelled

ESO Top News - Thu, 07/24/2025 - 4:56am

The journey to launch is picking up pace for Europe’s MetOp Second Generation weather satellite – which hosts the Copernicus Sentinel-5 as part of its instrument package. Specialists at Europe’s Spaceport in Kourou have completed the critical and hazardous task of fuelling the satellite, marking a major milestone in its final preparations for liftoff.

Categories: Astronomy

The time you take an oral exam could affect whether you pass or fail

New Scientist Space - Cosmology - Thu, 07/24/2025 - 1:00am
Midday seems to be the optimal time to take an oral exam at university, which could be due to students not generally being early risers
Categories: Astronomy

The time you take an oral exam could affect whether you pass or fail

New Scientist Space - Space Headlines - Thu, 07/24/2025 - 1:00am
Midday seems to be the optimal time to take an oral exam at university, which could be due to students not generally being early risers
Categories: Astronomy

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APOD - Thu, 07/24/2025 - 12:00am


Categories: Astronomy, NASA

<p><a href="https://apod.nasa.gov/apod

APOD - Thu, 07/24/2025 - 12:00am


Categories: Astronomy, NASA

Betelgeuse Isn't Alone. It Has A Very Dim Companion

Universe Today - Wed, 07/23/2025 - 10:04pm

Astronomers have discovered a companion star in an incredibly tight orbit around Betelgeuse using the NASA and U.S. National Science Foundation-funded ‘Alopeke' instrument on Gemini North, one half of the International Gemini Observatory, partly funded by the NSF and operated by NSF NOIRLab. This discovery answers the longstanding mystery of the star’s varying brightness and provides insight into the physical mechanisms behind other variable red supergiants.

Categories: Astronomy