Latest news with #galaxycollision
Yahoo
2 days ago
- General
- Yahoo
Is this the end of the world? How a galactic pile-up could bring Earth's violent finish: Cosmic ‘coin flip'
Forget killer asteroids and nuclear annihilation — Earth's ultimate fate may hinge on a cosmic coin toss. Astronomers have revealed that our Milky Way galaxy has a 50/50 chance of colliding with its massive neighbor, the Andromeda galaxy, sometime in the next 10 billion years — an intergalactic smash-up that could fling our solar system into deep space or swallow Earth whole. Cue the sci-fi panic — or not. 'It used to appear destined to merge with Andromeda forming a colossal 'Milkomeda,'' said Professor Alis Deason, a computational cosmologist at Durham University, per The Daily Mail. 'Now, there is a chance that we could avoid this fate entirely.' In other words: The end of the world may not be as inevitable as we thought — at least not from the galaxy next door. The new study, published in 'Nature Astronomy,' analyzed 100,000 simulations of the Milky Way's future. The findings — thanks to refined data from NASA's Hubble Space Telescope and the European Space Agency's Gaia mission — dramatically downshifted previous predictions of a guaranteed galactic pile-up in just 5 billion years. 'In short, the probability went from near-certainty to a coin flip,' lead author Dr. Till Sawala, of the University of Helsinki, revealed to The findings factor in the gravitational tug of neighboring galaxies — most notably the Large Magellanic Cloud, a much smaller satellite galaxy whose pull may be yanking the Milky Way off a crash course. 'The main difference between our research and previous studies is that we benefited from newer and more precise data, and that we considered a more complete system,' Sawala said to the site. While a 220,000 mph galaxy-on-galaxy collision sounds catastrophic, astronomers say a head-on impact is 'very unlikely.' In fact, only 2% of simulations showed a direct hit within 5 billion years. Most scenarios had the galaxies swirling toward each other, possibly merging much later — or not at all. Still, if they do collide, it could be a literal star show. 'We see external galaxies often colliding and merging with other galaxies, sometimes producing the equivalent of cosmic fireworks,' said Durham cosmologist Professor Carlos Frenk, via The Daily Mail. 'Until now, we thought this was the fate that awaited our Milky Way galaxy. We now know that there is a very good chance that we may avoid that scary destiny.' But even if Earth sidesteps this stellar shakedown, don't get too comfortable. As The Post previously reported, our sun is expected to become a bloated red giant in about 5 billion years — likely boiling away Earth's oceans or swallowing the planet entirely. So, yeah. Pick your apocalypse. 'If [the Milky Way-Andromeda collision] happens, it might take place after the Earth and the sun no longer exist,' Sawala told The Daily Mail. 'Even if it happens before that, it's very unlikely that something would happen to Earth in this case.' Translation: By the time the universe gets around to smashing the Milky Way, we'll probably already be toast. Still, some experts say galactic fate is more than just an astronomer's obsession. 'The fate of our Milky Way galaxy is a subject of broad interest — not just to astronomers,' Raja GuhaThakurta of the University of California, Santa Cruz, told the Associated Press. And while the galaxy might survive — barely — we may not. As Sawala put it: 'Of course, there is also a very significant chance that humanity will bring an end to itself still much before that, without any need for astrophysical help.' Talk about a stellar self-own.
South China Morning Post
3 days ago
- General
- South China Morning Post
Milky Way's chance of colliding with neighbour galaxy? 50-50, billions of years from now
It turns out that looming collision between our Milky Way and Andromeda galaxies might not happen after all. Advertisement Astronomers reported Monday that the probability of the two spiral galaxies colliding is less than previously thought, with a 50-50 chance within the next 10 billion years. That is essentially a coin flip, but still better odds than previous estimates and farther out in time. 'As it stands, proclamations of the impending demise of our galaxy seem greatly exaggerated,' the Finnish-led team wrote in a study appearing in Nature Astronomy. While good news for the Milky Way galaxy, the latest forecast may be moot for humanity. 'We likely won't live to see the benefit,' lead author Till Sawala of the University of Helsinki said in an email. Advertisement Already more than 4.5 billion years old, the sun is on course to run out of energy and die in another 5 billion years or so, but not before becoming so big it will engulf Mercury, Venus and possibly Earth. Even if it does not swallow Earth, the home planet will be left a burnt ball, its oceans long since boiled away.
News.com.au
3 days ago
- General
- News.com.au
‘Coin flip': 50-50 chance Milky Way will be destroyed in collision with Andromeda galaxy
The Milky Way may not have a catastrophic collision with another huge galaxy as has been predicted, computer simulations revealed Monday, giving our home galaxy a coin-flip chance of avoiding destruction. But don't worry either way: no galactic smash-up is expected for billions of years, long after our ageing Sun will have burnt away all life on Earth. The Milky Way and the even-larger galaxy Andromeda are speeding towards each other at 100 kilometres (60 miles) a second, and scientists have long predicted they will collide in around 4.5 billion years. That would be bad news for our neighbourhood. Previous research has suggested that the Sun — and our Earth — could wind up in the centre of this newly merged 'Milkomeda' galaxy and get sucked into its supermassive black hole. Alternatively, the Sun could be shot out into the emptiness of intergalactic space. However 'proclamations of the impending demise of our galaxy seem greatly exaggerated', according to a new study in the journal Nature Astronomy. There is only a roughly 50 per cent chance the Milky Way and Andromeda will smash into each other in the next 10 billion years, the international team of astrophysicists determined. 'It's basically a coin flip,' lead study author Till Sawala of the University of Helsinki told AFP. The researchers ran more than 100,000 computer simulations of our universe's future, using new observations from space telescopes. A galaxy merger in the next five billion years is 'extremely unlikely', Sawala said. Much more likely is that the galaxies will zoom relatively close to each other — say, a little under 500,000 light years away. In only half of the simulations did dark matter then eventually drag the two galaxies together into a cataclysmic embrace. But this would likely only occur in around eight billion years — long after our Sun has died, the researchers found. 'So it could be that our galaxy will end up destroyed,' Sawala said. 'But it's also possible that our galaxy and Andromeda will orbit one another for tens of billions of years — we just don't know.' 'The fate of our galaxy is still completely open,' the study summarised. The researchers emphasised that their findings did not mean that previous calculations were incorrect, just that they had used newer observations and taken into account the effect of more satellite galaxies. Future data releases from Europe's recently retired Gaia space telescope as well as Hubble could provide a definitive answer to this question within the next decade, Sawala predicted. How much all this all matters to us is a matter of debate. The Sun is expected to make Earth inhospitable to life in around a billion years. 'We might have some emotional attachment' to what happens after we're gone, Sawala said. 'I might prefer the Milky Way not to collide with Andromeda, even though it has absolutely no relevance to my own life — or the lives of my children or great-great grandchildren.'
CNA
3 days ago
- General
- CNA
Study sees lower chances of Milky Way crashing into Andromeda galaxy
WASHINGTON :The Milky Way and the neighboring Andromeda galaxy are currently hurtling through space toward each other at a speed of about 250,000 miles per hour (400,000 kph), setting up a possible future galactic collision that would wreck both of them. But how likely is this cosmic crash? While previous research forecast it to occur roughly 4-4.5 billion years from now, a new study that uses recent observational data and adds fresh variables indicates that a collision is far from certain. It puts the likelihood of a collision in the next 5 billion years at less than 2 per cent and one in the next 10 billion years at about 50 per cent. Galactic mergers are not like a demolition derby, with stars and planets crashing into each other, but rather a complicated blending on an immense scale. "The future collision - if it happens - would be the end of both the Milky Way and Andromeda," said University of Helsinki astrophysicist Till Sawala, lead author of the study published on Monday in the journal Nature Astronomy, with the structure of both being destroyed and a new galaxy with an elliptical shape arising from the merger. "If a merger happens, it is more likely to occur 7-8 billion years in the future. But we find that based on the current data, we cannot predict the time of a merger, if it happens at all," Sawala said. The two galaxies currently are around 2.5 billion light-years from each other. A light-year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). The potential collision is so far in the future that Earth by that time is forecast to become a completely different kind of place. Our planet is expected to be rendered uninhabitable roughly a billion years from now, with the sun becoming so hot that it will boil away our planet's sun is one of the Milky Way's many billions of stars. The total mass of our spiral-shaped galaxy - including its stars and interstellar gas as well as its dark matter, which is invisible material whose presence is revealed by its gravitational effects - is estimated at approximately one trillion times the mass of the sun. The Andromeda galaxy has a shape and total mass similar to the Milky Way's. The researchers simulated the Milky Way's movement over the next 10 billion years using updated data from the Gaia and Hubble space telescopes and various ground-based telescopes as well as revised galactic mass estimates. Other nearby galaxies are forecast to factor into whether a collision occurs. Previous research accounted for the gravitational influence of the Triangulum galaxy, also called Messier 33 or M33, which is about half the size of the Milky Way and Andromeda, but did consider the Large Magellanic Cloud, a smaller satellite galaxy of the Milky Way, as this study does. "We find that if only M33 is added to the two-body system, the chance of a Milky Way-Andromeda merger actually increases, but the inclusion of the Large Magellanic Cloud has the opposite effect," Sawala said. The researchers concluded that a merger between the Milky Way and the Large Magellanic Cloud is almost certain within the next 2 billion years, long before a potential collision with Andromeda. One noteworthy difference between the Milky Way and Andromeda is the mass of the supermassive black holes at their centers. The Milky Way's Sagittarius A*, or Sgr A*, is about 4 million times the mass of the sun. Its Andromeda counterpart is about 100 million the sun's mass. "Collisions between stars are very unlikely, but the two supermassive black holes would sink to the center of the newly formed galaxy, where they would eventually merge," Sawala said. Galactic mergers have occurred since the universe's early stages and are particularly common in areas of the universe where galaxies are clustered together. "In the early universe, galaxy mergers were much more frequent, so the first mergers would have occurred very shortly after the first galaxies had formed," Sawala said. "Minor mergers - with much smaller galaxies - happen more frequently. Indeed, the Milky Way is currently merging with several dwarf galaxies," Sawala said.
The Independent
3 days ago
- General
- The Independent
The Milky Way was on a collision course with a neighboring galaxy. Not anymore
More than a decade ago, scientists predicted our Milky Way galaxy and neighboring Andromeda would collide in four billion years, resulting in a 'makeover' of our solar system. Now, that is unlikely — at least within the expected timeframe. 'We see external galaxies often colliding and merging with other galaxies, sometimes producing the equivalent of cosmic fireworks when gas, driven to the center of the merger remnant, feeds a central black hole emitting an enormous amount of radiation, before irrevocably falling into the hole,' explained Durham University Professor Carlos Frenk. 'Until now we thought this was the fate that awaited our Milky Way galaxy, ' he said in a statement. 'We now know that there is a very good chance that we may avoid that scary destiny.' Previous research from NASA astronomers had found that the collision with our closest neighbor galaxy would fling the sun to a new region of space, although the Earth would not be destroyed. The stars would be sent into different orbits. Right now, the galaxies are heading toward each other with a speed of approximately 62 miles per second. But, following 100,000 simulations of both galaxies based on the latest observational data from NASA's Hubble and the European Space Agency's Gaia space telescopes, the authors of the study that was published in the journal Nature Astronomy found just a 2 percent probability that the Milky Way and Andromeda would crash into each other over the course of the next five billion years. In more than half of the scenarios, the galaxies experienced at least one close encounter before they lost enough orbital energy to collide and merge. However, that would occur in some eight-to-10 billion years. By that time, the sun may have burnt itself out when it runs out of hydrogen, consuming the Earth. But, in most other cases, the galaxies pass each other by without incident, although there is room for uncertainty. Furthermore, the authors assert that previous research was not incorrect, but that they were able to incorporate more variables in their simulations. 'While some earlier works had focused on the interaction between the Milky Way, Andromeda, and the Triangulum galaxy, we also include the effect of the Large Magellanic Cloud,' lead author Dr. Till Sawala, of the University of Helsinki, said. The cloud is a dwarf galaxy that orbits the Milky Way. 'Although its mass is only around 15 percent of the Milky Way's, its gravitational pull directed perpendicular to the orbit with Andromeda perturbs the Milky Way's motion enough to significantly reduce the chance of a merger with the Andromeda galaxy.' However, the authors are already looking to update their findings with new data. The European Space Agency's Gaia space telescope will soon provide more precise measurements of crucial factors within the galaxies, including the motion of Andromeda. Still, Frenk said the results are a 'testimony' to the power of large supercomputers. 'When I see the results of our calculations, I am astonished that we are able to simulate with such precision the evolution of gigantic collections of stars over billions of years and figure out their ultimate fate,' he added.
