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There may be a surprising upside to losing coral reefs as oceans warm
There may be a surprising upside to losing coral reefs as oceans warm
Two space vets added to Astronaut Hall of Fame as one awaits launch
What's at the center of Mars? Maybe the stench of rotten eggs
A Star Like No Other
A Star Like No Other
An unusual star (circled in white at right) behaving like no other seen before and its surroundings are featured in this composite image released on May 28, 2025. A team of astronomers combined data from NASA’s Chandra X-ray Observatory and the Square Kilometer Array Pathfinder (ASKAP) radio telescope on Wajarri Country in Australia to study the discovered object, known as ASKAP J1832−0911 (ASKAP J1832 for short).
ASKAP J1832 belongs to a class of objects called “long period radio transients” discovered in 2022 that vary in radio wave intensity in a regular way over tens of minutes. This is thousands of times longer than the length of the repeated variations seen in pulsars, which are rapidly spinning neutron stars that have repeated variations multiple times a second. ASKAP J1832 cycles in radio wave intensity every 44 minutes, placing it into this category of long period radio transients. Using Chandra, the team discovered that ASKAP J1832 is also regularly varying in X-rays every 44 minutes. This is the first time that such an X-ray signal has been found in a long period radio transient.
Image credit: X-ray: NASA/CXC/ICRAR, Curtin Univ./Z. Wang et al.; Infrared: NASA/JPL/CalTech/IPAC; Radio: SARAO/MeerKAT; Image processing: NASA/CXC/SAO/N. Wolk
A Star Like No Other
An unusual star (circled in white at right) behaving like no other seen before and its surroundings are featured in this composite image released on May 28, 2025. A team of astronomers combined data from NASA’s Chandra X-ray Observatory and the Square Kilometer Array Pathfinder (ASKAP) radio telescope on Wajarri Country in Australia to study the discovered object, known as ASKAP J1832−0911 (ASKAP J1832 for short).
ASKAP J1832 belongs to a class of objects called “long period radio transients” discovered in 2022 that vary in radio wave intensity in a regular way over tens of minutes. This is thousands of times longer than the length of the repeated variations seen in pulsars, which are rapidly spinning neutron stars that have repeated variations multiple times a second. ASKAP J1832 cycles in radio wave intensity every 44 minutes, placing it into this category of long period radio transients. Using Chandra, the team discovered that ASKAP J1832 is also regularly varying in X-rays every 44 minutes. This is the first time that such an X-ray signal has been found in a long period radio transient.
Image credit: X-ray: NASA/CXC/ICRAR, Curtin Univ./Z. Wang et al.; Infrared: NASA/JPL/CalTech/IPAC; Radio: SARAO/MeerKAT; Image processing: NASA/CXC/SAO/N. Wolk
Best quantum 'transistor' yet could lead to more accurate computers
Best quantum 'transistor' yet could lead to more accurate computers
$800 million, 13 years, and still no release date — the state of Star Citizen in 2025
Incredible auroras delight stargazers in New Zealand | Space photo of the day for June 2, 2025
Private Japanese spacecraft aims to land in the moon's 'Sea of Cold' this week
What’s Up: June 2025 Skywatching Tips from NASA
Venus and Saturn separate, while Mars hangs out in the evening. Plus the June solstice, and dark skies reveal our home galaxy in all of its glory.
Skywatching HighlightsAll Month – Planet Visibility:
- Venus: Rises about 2 hours before the Sun in June, and shines very brightly, low in the eastern sky, in the morning all month.
- Mars: Visible in the west for a couple of hours after sunset all month. Drops lower in the sky as June continues, and passes very close to Regulus in the constellation Leo on June 16 and 17. (They will be about half a degree apart, or the width of the full moon.)
- Jupiter: Visible quite low in the west after sunset for the first week of June, then lost in the Sun’s glare after. Will re-appear in July in the morning sky.
- Mercury: Becomes visible low in the west about 30 to 45 minutes after sunset in the last week and a half of June.
- Saturn: Rises around 3 a.m. in early June, and around 1 a.m. by the end of the month. Begins the month near Venus in the dawn sky, but rapidly pulls away, rising higher as June goes on.
Daily Highlights:
June 19 – Moon & Saturn – The third-quarter moon appears right next Saturn this morning in the hours before dawn. The pair rise in the east together around 1:30 a.m.
June 22 – Moon & Venus – Venus rises this morning next to a slender and elegant crescent moon. Look for them in the east between about 3 a.m. and sunrise.
June 20 – June Solstice – The June solstice is on June 20 for U.S. time zones (June 21 UTC). The Northern Hemisphere’s tilt toward the Sun is greatest on this day. This means the Sun travels its longest, highest arc across the sky all year for those north of the equator.
June 16 & 17 – Mars & Regulus – Mars passes quite close to the bright bluish-white star Regulus, known as the “heart” of the lion constellation, Leo. They will appear about as far apart as the width of the full moon, and should be an excellent sight in binoculars or a small telescope.
June 21-30 – Mercury becomes visible – For those with a clear view to the western horizon, Mercury becomes visible for a brief period each evening at the end of June. Look for it quite low in the sky starting 30 to 45 minutes after the Sun sets.
All month – Mars: The Red Planet can be observed for a couple of hours after dark all month. It is noticeably dimmer than it appeared in early May, as Earth speeds away in its orbit, putting greater distance between the two worlds.
All month – Milky Way core: The bright central bulge of our home galaxy, the Milky Way, is visible all night in June, continuing through August. It is best observed from dark sky locations far from bright city lights, and appears as a faint, cloud-like band arching across the sky toward the south.
TranscriptWhat’s Up for June? Mars grazes the lion’s heart, a connection to ancient times, and the galaxy in all its glory.
June Planet Observing
Starting with planet observing for this month, find Saturn and Venus in the eastern sky during the couple of hours before dawn each morning throughout the month. Saturn rapidly climbs higher in the sky each day as the month goes on. You’ll find the third quarter moon next to Saturn on the 19th, and a crescent moon next to Venus on the 22nd.
Sky chart showing Mercury with the crescent Moon following sunset in late June, 2025. NASA/JPL-Caltech
Mercury pops up toward the end of the month. Look for it quite low in the west, just as the glow of sunset is fading. It’s highest and most visible on the 27th.
Mars is still visible in the couple of hours after sunset toward the west, though it’s noticeably fainter than it was in early May. Over several days in mid-June, Mars passes quite close to Regulus, the bright star at the heart of the constellation Leo, the lion. Have a peek on the 16th and 17th with binoculars or a small telescope to see them as close as the width of the full moon.
Sky chart showing Mars close to Regulus in the evening sky on June 16, 2025. NASA/JPL-Caltech
Milky Way Core Season
June means that Milky Way “Core Season” is here. This is the time of year when the Milky Way is visible as a faint band of hazy light arching across the sky all night. You just need to be under dark skies away from bright city lights to see it. What you’re looking at is the bright central core of our home galaxy, seen edge-on, from our position within the galaxy’s disk.
Long-exposure photos make the Milky Way’s bright stars and dark dust clouds even clearer. And while our eyes see it in visible light, NASA telescopes observe the galaxy across the spectrum — peering through dust to help us better understand our origins.
However you observe it, getting out under the Milky Way in June is a truly remarkable way to connect with the cosmos.
June Solstice
June brings the summer solstice for those north of the equator, which is the winter solstice for those south of the equator. In the Northern Hemisphere, this is when the Sun is above the horizon longer than any other day, making it the longest day of the year. The situation is reversed for the Southern Hemisphere, where it’s the shortest day of the year.
Illustration from a NASA animation showing the tilt of Earth’s axis in June (Northern Hemisphere summer) with respect to the Sun, the planet’s orbit, and the North Star, Polaris. NASA’s Goddard Space Flight Center
Earth’s tilted rotation is the culprit. The tilt is always in the same direction, with the North Pole always pointing toward Polaris, the North Star. And since that tilt stays the same, year round, when we’re on one side of the Sun in winter, the north part of the planet is tilted away from the Sun. But six months later, the planet moves halfway around its annual path, carrying us to the opposite side of Earth’s orbit, and the northern part of the planet now finds itself tilted toward the Sun. The June solstice is when this tilt is at its maximum. This is summertime for the north, bringing long days, lots more sunlight, and warmer temperatures.
The June solstice marks a precise moment in Earth’s orbit – a consistent astronomical signpost that humans have observed for millennia. Ancient structures from Stonehenge to Chichén Itzá were built, in part, to align with the solstices, demonstrating how important these celestial events were to many cultures.
So whether you’re experiencing long summer days in the northern hemisphere or the brief daylight hours of winter in the south, find a quiet spot to watch the sunset on this special day and you’ll be participating in one of humanity’s oldest astronomical traditions, connecting you to observers across thousands of years of human history.
Here are the phases of the Moon for June.
The phases of the Moon for June 2025.
You can stay up to date on all of NASA’s missions exploring the solar system and beyond at NASA Science. I’m Preston Dyches from NASA’s Jet Propulsion Laboratory, and that’s What’s Up for this month.
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What’s Up: June 2025 Skywatching Tips from NASA
Venus and Saturn separate, while Mars hangs out in the evening. Plus the June solstice, and dark skies reveal our home galaxy in all of its glory.
Skywatching HighlightsAll Month – Planet Visibility:
- Venus: Rises about 2 hours before the Sun in June, and shines very brightly, low in the eastern sky, in the morning all month.
- Mars: Visible in the west for a couple of hours after sunset all month. Drops lower in the sky as June continues, and passes very close to Regulus in the constellation Leo on June 16 and 17. (They will be about half a degree apart, or the width of the full moon.)
- Jupiter: Visible quite low in the west after sunset for the first week of June, then lost in the Sun’s glare after. Will re-appear in July in the morning sky.
- Mercury: Becomes visible low in the west about 30 to 45 minutes after sunset in the last week and a half of June.
- Saturn: Rises around 3 a.m. in early June, and around 1 a.m. by the end of the month. Begins the month near Venus in the dawn sky, but rapidly pulls away, rising higher as June goes on.
Daily Highlights:
June 19 – Moon & Saturn – The third-quarter moon appears right next Saturn this morning in the hours before dawn. The pair rise in the east together around 1:30 a.m.
June 22 – Moon & Venus – Venus rises this morning next to a slender and elegant crescent moon. Look for them in the east between about 3 a.m. and sunrise.
June 20 – June Solstice – The June solstice is on June 20 for U.S. time zones (June 21 UTC). The Northern Hemisphere’s tilt toward the Sun is greatest on this day. This means the Sun travels its longest, highest arc across the sky all year for those north of the equator.
June 16 & 17 – Mars & Regulus – Mars passes quite close to the bright bluish-white star Regulus, known as the “heart” of the lion constellation, Leo. They will appear about as far apart as the width of the full moon, and should be an excellent sight in binoculars or a small telescope.
June 21-30 – Mercury becomes visible – For those with a clear view to the western horizon, Mercury becomes visible for a brief period each evening at the end of June. Look for it quite low in the sky starting 30 to 45 minutes after the Sun sets.
All month – Mars: The Red Planet can be observed for a couple of hours after dark all month. It is noticeably dimmer than it appeared in early May, as Earth speeds away in its orbit, putting greater distance between the two worlds.
All month – Milky Way core: The bright central bulge of our home galaxy, the Milky Way, is visible all night in June, continuing through August. It is best observed from dark sky locations far from bright city lights, and appears as a faint, cloud-like band arching across the sky toward the south.
TranscriptWhat’s Up for June? Mars grazes the lion’s heart, a connection to ancient times, and the galaxy in all its glory.
June Planet Observing
Starting with planet observing for this month, find Saturn and Venus in the eastern sky during the couple of hours before dawn each morning throughout the month. Saturn rapidly climbs higher in the sky each day as the month goes on. You’ll find the third quarter moon next to Saturn on the 19th, and a crescent moon next to Venus on the 22nd.
Sky chart showing Mercury with the crescent Moon following sunset in late June, 2025. NASA/JPL-CaltechMercury pops up toward the end of the month. Look for it quite low in the west, just as the glow of sunset is fading. It’s highest and most visible on the 27th.
Mars is still visible in the couple of hours after sunset toward the west, though it’s noticeably fainter than it was in early May. Over several days in mid-June, Mars passes quite close to Regulus, the bright star at the heart of the constellation Leo, the lion. Have a peek on the 16th and 17th with binoculars or a small telescope to see them as close as the width of the full moon.
Sky chart showing Mars close to Regulus in the evening sky on June 16, 2025. NASA/JPL-CaltechMilky Way Core Season
June means that Milky Way “Core Season” is here. This is the time of year when the Milky Way is visible as a faint band of hazy light arching across the sky all night. You just need to be under dark skies away from bright city lights to see it. What you’re looking at is the bright central core of our home galaxy, seen edge-on, from our position within the galaxy’s disk.
Long-exposure photos make the Milky Way’s bright stars and dark dust clouds even clearer. And while our eyes see it in visible light, NASA telescopes observe the galaxy across the spectrum — peering through dust to help us better understand our origins.
However you observe it, getting out under the Milky Way in June is a truly remarkable way to connect with the cosmos.
June Solstice
June brings the summer solstice for those north of the equator, which is the winter solstice for those south of the equator. In the Northern Hemisphere, this is when the Sun is above the horizon longer than any other day, making it the longest day of the year. The situation is reversed for the Southern Hemisphere, where it’s the shortest day of the year.
Illustration from a NASA animation showing the tilt of Earth’s axis in June (Northern Hemisphere summer) with respect to the Sun, the planet’s orbit, and the North Star, Polaris. NASA’s Goddard Space Flight CenterEarth’s tilted rotation is the culprit. The tilt is always in the same direction, with the North Pole always pointing toward Polaris, the North Star. And since that tilt stays the same, year round, when we’re on one side of the Sun in winter, the north part of the planet is tilted away from the Sun. But six months later, the planet moves halfway around its annual path, carrying us to the opposite side of Earth’s orbit, and the northern part of the planet now finds itself tilted toward the Sun. The June solstice is when this tilt is at its maximum. This is summertime for the north, bringing long days, lots more sunlight, and warmer temperatures.
The June solstice marks a precise moment in Earth’s orbit – a consistent astronomical signpost that humans have observed for millennia. Ancient structures from Stonehenge to Chichén Itzá were built, in part, to align with the solstices, demonstrating how important these celestial events were to many cultures.
So whether you’re experiencing long summer days in the northern hemisphere or the brief daylight hours of winter in the south, find a quiet spot to watch the sunset on this special day and you’ll be participating in one of humanity’s oldest astronomical traditions, connecting you to observers across thousands of years of human history.
Here are the phases of the Moon for June.
The phases of the Moon for June 2025.You can stay up to date on all of NASA’s missions exploring the solar system and beyond at NASA Science. I’m Preston Dyches from NASA’s Jet Propulsion Laboratory, and that’s What’s Up for this month.
Keep Exploring Discover More Topics From NASA
Skywatching
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Solar System Exploration
Moons
The Milky Way may not collide with neighboring galaxy Andromeda after all: 'From near-certainty to a coin flip'
Apocalypse When? Hubble Casts Doubt on Certainty of Galactic Collision
- Hubble Home
- Overview
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NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and B. Whitmore (STScI)
As far back as 1912, astronomers realized that the Andromeda galaxy — then thought to be only a nebula — was headed our way. A century later, astronomers using NASA’s Hubble Space Telescope were able to measure the sideways motion of Andromeda and found it was so negligible that an eventual head-on collision with the Milky Way seemed almost certain.
A smashup between our own galaxy and Andromeda would trigger a firestorm of star birth, supernovae, and maybe toss our Sun into a different orbit. Simulations had suggested it was as inevitable as, in the words of Benjamin Franklin, “death and taxes.”
But now a new study using data from Hubble and the European Space Agency’s (ESA) Gaia space telescope says “not so fast.” Researchers combining observations from the two space observatories re-examined the long-held prediction of a Milky Way – Andromeda collision, and found it is far less inevitable than astronomers had previously suspected.
“We have the most comprehensive study of this problem today that actually folds in all the observational uncertainties,” said Till Sawala, astronomer at the University of Helsinki in Finland and lead author of the study, which appears today in the journal Nature Astronomy.
His team includes researchers at Durham University, United Kingdom; the University of Toulouse, France; and the University of Western Australia. They found that there is approximately a 50-50 chance of the two galaxies colliding within the next 10 billion years. They based this conclusion on computer simulations using the latest observational data.
These galaxy images illustrate three possible encounter scenarios between our Milky Way and the neighboring Andromeda galaxy. Top left: Galaxies M81 and M82. Top right: NGC 6786, a pair of interacting galaxies. Bottom: NGC 520, two merging galaxies. Science: NASA, ESA, STScI, DSS, Till Sawala (University of Helsinki); Image Processing: Joseph DePasquale (STScI)Sawala emphasized that predicting the long-term future of galaxy interactions is highly uncertain, but the new findings challenge the previous consensus and suggest the fate of the Milky Way remains an open question.
“Even using the latest and most precise observational data available, the future of the Local Group of several dozen galaxies is uncertain. Intriguingly, we find an almost equal probability for the widely publicized merger scenario, or, conversely, an alternative one where the Milky Way and Andromeda survive unscathed,” said Sawala.
The collision of the two galaxies had seemed much more likely in 2012, when astronomers Roeland van der Marel and Tony Sohn of the Space Telescope Science Institute in Baltimore, Maryland published a detailed analysis of Hubble observations over a five-to-seven-year period, indicating a direct impact in no more than 5 billion years.
“It’s somewhat ironic that, despite the addition of more precise Hubble data taken in recent years, we are now less certain about the outcome of a potential collision. That’s because of the more complex analysis and because we consider a more complete system. But the only way to get to a new prediction about the eventual fate of the Milky Way will be with even better data,” said Sawala.
100,000 Crash-Dummy SimulationsAstronomers considered 22 different variables that could affect the potential collision between our galaxy and our neighbor, and ran 100,000 simulations called Monte Carlo simulations stretching to 10 billion years into the future.
“Because there are so many variables that each have their errors, that accumulates to rather large uncertainty about the outcome, leading to the conclusion that the chance of a direct collision is only 50% within the next 10 billion years,” said Sawala.
“The Milky Way and Andromeda alone would remain in the same plane as they orbit each other, but this doesn’t mean they need to crash. They could still go past each other,” said Sawala.
Researchers also considered the effects of the orbits of Andromeda’s large satellite galaxy, M33, and a satellite galaxy of the Milky Way called the Large Magellanic Cloud (LMC).
“The extra mass of Andromeda’s satellite galaxy M33 pulls the Milky Way a little bit more towards it. However, we also show that the LMC pulls the Milky Way off the orbital plane and away from Andromeda. It doesn’t mean that the LMC will save us from that merger, but it makes it a bit less likely,” said Sawala.
In about half of the simulations, the two main galaxies fly past each other separated by around half a million light-years or less (five times the Milky Way’s diameter). They move outward but then come back and eventually merge in the far future. The gradual decay of the orbit is caused by a process called dynamical friction between the vast dark-matter halos that surround each galaxy at the beginning.
In most of the other cases, the galaxies don’t even come close enough for dynamical friction to work effectively. In this case, the two galaxies can continue their orbital waltz for a very long time.
The new result also still leaves a small chance of around 2% for a head-on collision between the galaxies in only 4 to 5 billion years. Considering that the warming Sun makes Earth uninhabitable in roughly 1 billion years, and the Sun itself will likely burn out in 5 billion years, a collision with Andromeda is the least of our cosmic worries.
The Hubble Space Telescope has been operating for over 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.
Explore MoreHubble Provides Bird’s-Eye View of Andromeda Galaxy’s Ecosystem (2025)
Hubble Shows Milky Way is Destined for Head-on Collision with Andromeda Galaxy (2012)
Galaxy Details and Mergers
Hubble Traces Hidden History of Andromeda Galaxy (2025)
Hubble’s High-Definition Panoramic View of the Andromeda Galaxy (2015)
Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Related Images & Videos Milky Way and Andromeda Encounters
This selection of images of external galaxies illustrates three encounter scenarios between our Milky Way and the neighboring Andromeda galaxy. Top left: Galaxies M81 and M82. Top right: NGC 6786, a pair of interacting galaxies. Bottom: NGC 520, two merging galaxies.
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 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.
Hubble Science Highlights
Hubble Images
Hubble News
Apocalypse When? Hubble Casts Doubt on Certainty of Galactic Collision
- Hubble Home
- Overview
- Impact & Benefits
- Science
- Observatory
- Team
- Multimedia
- News
- More
NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and B. Whitmore (STScI)
As far back as 1912, astronomers realized that the Andromeda galaxy — then thought to be only a nebula — was headed our way. A century later, astronomers using NASA’s Hubble Space Telescope were able to measure the sideways motion of Andromeda and found it was so negligible that an eventual head-on collision with the Milky Way seemed almost certain.
A smashup between our own galaxy and Andromeda would trigger a firestorm of star birth, supernovae, and maybe toss our Sun into a different orbit. Simulations had suggested it was as inevitable as, in the words of Benjamin Franklin, “death and taxes.”
But now a new study using data from Hubble and the European Space Agency’s (ESA) Gaia space telescope says “not so fast.” Researchers combining observations from the two space observatories re-examined the long-held prediction of a Milky Way – Andromeda collision, and found it is far less inevitable than astronomers had previously suspected.
“We have the most comprehensive study of this problem today that actually folds in all the observational uncertainties,” said Till Sawala, astronomer at the University of Helsinki in Finland and lead author of the study, which appears today in the journal Nature Astronomy.
His team includes researchers at Durham University, United Kingdom; the University of Toulouse, France; and the University of Western Australia. They found that there is approximately a 50-50 chance of the two galaxies colliding within the next 10 billion years. They based this conclusion on computer simulations using the latest observational data.
These galaxy images illustrate three possible encounter scenarios between our Milky Way and the neighboring Andromeda galaxy. Top left: Galaxies M81 and M82. Top right: NGC 6786, a pair of interacting galaxies. Bottom: NGC 520, two merging galaxies. Science: NASA, ESA, STScI, DSS, Till Sawala (University of Helsinki); Image Processing: Joseph DePasquale (STScI)Sawala emphasized that predicting the long-term future of galaxy interactions is highly uncertain, but the new findings challenge the previous consensus and suggest the fate of the Milky Way remains an open question.
“Even using the latest and most precise observational data available, the future of the Local Group of several dozen galaxies is uncertain. Intriguingly, we find an almost equal probability for the widely publicized merger scenario, or, conversely, an alternative one where the Milky Way and Andromeda survive unscathed,” said Sawala.
The collision of the two galaxies had seemed much more likely in 2012, when astronomers Roeland van der Marel and Tony Sohn of the Space Telescope Science Institute in Baltimore, Maryland published a detailed analysis of Hubble observations over a five-to-seven-year period, indicating a direct impact in no more than 5 billion years.
“It’s somewhat ironic that, despite the addition of more precise Hubble data taken in recent years, we are now less certain about the outcome of a potential collision. That’s because of the more complex analysis and because we consider a more complete system. But the only way to get to a new prediction about the eventual fate of the Milky Way will be with even better data,” said Sawala.
100,000 Crash-Dummy SimulationsAstronomers considered 22 different variables that could affect the potential collision between our galaxy and our neighbor, and ran 100,000 simulations called Monte Carlo simulations stretching to 10 billion years into the future.
“Because there are so many variables that each have their errors, that accumulates to rather large uncertainty about the outcome, leading to the conclusion that the chance of a direct collision is only 50% within the next 10 billion years,” said Sawala.
“The Milky Way and Andromeda alone would remain in the same plane as they orbit each other, but this doesn’t mean they need to crash. They could still go past each other,” said Sawala.
Researchers also considered the effects of the orbits of Andromeda’s large satellite galaxy, M33, and a satellite galaxy of the Milky Way called the Large Magellanic Cloud (LMC).
“The extra mass of Andromeda’s satellite galaxy M33 pulls the Milky Way a little bit more towards it. However, we also show that the LMC pulls the Milky Way off the orbital plane and away from Andromeda. It doesn’t mean that the LMC will save us from that merger, but it makes it a bit less likely,” said Sawala.
In about half of the simulations, the two main galaxies fly past each other separated by around half a million light-years or less (five times the Milky Way’s diameter). They move outward but then come back and eventually merge in the far future. The gradual decay of the orbit is caused by a process called dynamical friction between the vast dark-matter halos that surround each galaxy at the beginning.
In most of the other cases, the galaxies don’t even come close enough for dynamical friction to work effectively. In this case, the two galaxies can continue their orbital waltz for a very long time.
The new result also still leaves a small chance of around 2% for a head-on collision between the galaxies in only 4 to 5 billion years. Considering that the warming Sun makes Earth uninhabitable in roughly 1 billion years, and the Sun itself will likely burn out in 5 billion years, a collision with Andromeda is the least of our cosmic worries.
The Hubble Space Telescope has been operating for over 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.
Explore MoreHubble Provides Bird’s-Eye View of Andromeda Galaxy’s Ecosystem (2025)
Hubble Shows Milky Way is Destined for Head-on Collision with Andromeda Galaxy (2012)
Galaxy Details and Mergers
Hubble Traces Hidden History of Andromeda Galaxy (2025)
Hubble’s High-Definition Panoramic View of the Andromeda Galaxy (2015)
Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Related Images & Videos Milky Way and Andromeda Encounters
This selection of images of external galaxies illustrates three encounter scenarios between our Milky Way and the neighboring Andromeda galaxy. Top left: Galaxies M81 and M82. Top right: NGC 6786, a pair of interacting galaxies. Bottom: NGC 520, two merging galaxies.
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 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.
Hubble Science Highlights
Hubble Images
Hubble News
Engineered Viruses Are Transforming Neuroscience and Treating Brain Disease
Neuroscientists can now make precise genetic tweaks to the neurons that are most affected by brain diseases such as Parkinson’s, Huntington’s and ALS
Hubble and Gaia revisit fate of our galaxy
Over a decade’s worth of NASA/ESA Hubble Space Telescope data was used to re-examine the long-held prediction that the Milky Way galaxy will collide with the Andromeda galaxy in about 4.5 billion years. The astronomers found that, based on the latest observational data from Hubble and Gaia, there is only a 50-50 chance of the two galaxies colliding within the next 10 billion years.