Latest news with #Sawala
Yomiuri Shimbun
12-06-2025
- Science
- Yomiuri Shimbun
Lower Chance of Milky Way, Andromeda Merger Detected
NASA / ESA / Z. Levay and R. van der Marel / STScI / T. Hallas and A. Mellinger / Handout via Reuters A stage in the potential merger between the Milky Way galaxy, right, and the neighboring Andromeda galaxy, as viewed in Earth's night sky in 3.75 billion years is seen in this illustration released by NASA in May 2012. WASHINGTON (Reuters) — The Milky Way and the neighboring Andromeda galaxy are currently hurtling through space toward each other at a speed of about 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 billion-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% and one in the next 10 billion years at about 50%. 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 June 2 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 billion-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 million light-years from each other. The 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 Hill
06-06-2025
- Science
- The Hill
Milky Way has 50-50 chance of colliding with neighbor galaxy
The collision of the Milky Way and Andromeda galaxies that scientists believed was inevitable has a much lower probability than previously thought. The Associated Press reported Monday that astronomers in Finland have determined that our galaxy has a 50-50 chance of colliding with the neighboring Andromeda within the next 10 billion years. The previous theory suggested that the two galaxies had a high probability of colliding within the next five billion years. 'Based on the best available data, the fate of our galaxy is still completely open,' the team wrote in the study, which appeared in Nature Astronomy. A team led by University of Helsinki researcher Till Sawala simulated all possible scenarios using the latest data from NASA's Hubble Space Telescope and the European Space Agency's Gaia star-tracking mission. According to the simulation yielded some surprising results. 'A head-on collision is very unlikely, we found a less than 2 percent chance for that,' Sawala said. 'In most of the cases that lead to a merger, the two galaxies will indeed fly past each other at first, which will lead to a loss of orbital energy, and subsequently to a merger. 'How close they come on their first passage is very uncertain, however, and if they don't come very close, meaning if their distance is more than around 500,000 light-years, they might not merge at all,' the researcher added. Sawala said he was not prepared for what his team found. 'In short, the probability went from near-certainty to a coin flip,' Sawala noted. The study relied on newer and more precise information, and the team took into consideration a 'more complete system,' including the potential effects of the Large Magellanic Cloud. The dwarf galaxy is the Milky Way's largest satellite galaxy, reported. Ultimately, the astronomers found that the Milky Way and Andromeda would inevitably collide if the two galaxies' orbits come close enough to affect a gravitational pull on one another. If they stay well separated, the merger won't happen. While the scenarios indicated a less likely merger between the two, they found that the Milky Way is far more likely to cannibalize the Large Magellanic Cloud. The research indicates that this newly theorized merger is likely to happen over the next two billion years.
Yahoo
05-06-2025
- Science
- Yahoo
Milky Way has 50-50 chance of colliding with neighbor galaxy
(NewsNation) — The collision of the Milky Way and Andromeda galaxies that scientists believed was inevitable has a much lower probability than previously thought. The Associated Press reported Monday that astronomers in Finland have determined that our galaxy has a 50-50 chance of colliding with the neighboring Andromeda within the next 10 billion years. The previous theory suggested that the two galaxies had a high probability of colliding within the next five billion years. 'Based on the best available data, the fate of our galaxy is still completely open,' the team wrote in the study, which appeared in Nature Astronomy. A team led by University of Helsinki researcher Til Sawala simulated all possible scenarios using the latest data from NASA's Hubble Space Telescope and the European Space Agency's Gaia star-tracking mission. According to the simulation yielded some surprising results. Astronomers discover strange new celestial object in our Milky Way galaxy 'A head-on collision is very unlikely, we found a less than 2% chance for that,' Sawala said. 'In most of the cases that lead to a merger, the two galaxies will indeed fly past each other at first, which will lead to a loss of orbital energy, and subsequently to a merger. 'How close they come on their first passage is very uncertain, however, and if they don't come very close, meaning if their distance is more than around 500,000 light-years, they might not merge at all.' Sawala said he was not prepared for what his team found. 'In short, the probability went from near-certainty to a coin flip,' the researcher said. An accidental discovery at a planetarium opens a window into the universe's inner workings The study relied on newer and more precise information, and the team took into consideration a 'more complete system,' including the potential effects of the Large Magellanic Cloud. The dwarf galaxy is the Milky Way's largest satellite galaxy, reported. Ultimately, the astronomers found that the Milky Way and Andromeda would inevitably collide if the two galaxies' orbits come close enough to affect a gravitational pull on one another. If they stay well separated, the merger won't happen. While the scenarios indicated a less likely merger between the two, they found that the Milky Way is far more likely to cannibalize the Large Magellanic Cloud. The research indicates that this newly theorized merger is likely to happen over the next two billion years. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
The Hindu
04-06-2025
- General
- The Hindu
Looming clash between Milky Way, Andromeda may not happen after all
It turns out that looming collision between our Milky Way and Andromeda galaxies might not happen after all. 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's 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. 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 the earth. Even if it doesn't swallow the earth, the home planet will be left a burnt ball, its oceans long since boiled away. Sawala's international team relied on the latest observations by NASA's Hubble Space Telescope and the European Space Agency's Gaia star-surveying spacecraft to simulate the possible scenarios facing the Milky Way and next-door neighbour Andromeda. Both already collided with other galaxies in their ancient past and, according to many, seemed destined for a head-on crash. Past theories put a collision between the two — resulting in a new elliptical galaxy dubbed Milkomeda — as probable if not inevitable. Some predictions had that happening within 5 billion years, if not sooner. For this new study, the scientists relied on updated galaxy measurements to factor in the gravitational pull on the Milky Way's movement through the universe. They found that the effects of the neighbouring Triangulum galaxy increased the likelihood of a merger between the Milky Way and Andromeda, while the Large Magellanic Cloud decreased those chances. Despite lingering uncertainty over the position, motion and mass of all these galaxies, the scientists ended up with 50-50 odds of a collision within the next 10 billion years. 'The fate of our Milky Way galaxy is a subject of broad interest — not just to astronomers,' said Raja GuhaThakurta of the University of California, Santa Cruz, who was not involved in the study. A full-on collision, he noted, would transform our home galaxy from a disk of stars seen as a milky band of diffuse light across the sky into a milky blob. A harmless flyby of the two galaxies could leave this stellar disk largely undisturbed, thus preserving our galaxy's name. More work is needed before the Milky Way's fate can be predicted with accuracy, according to the researchers. Further insight should help scientists better understand what's happening among galaxies even deeper in the cosmos. While our galaxy's fate remains highly uncertain, the sun's future is 'pretty much sealed," according to Sawala. '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."
Yahoo
03-06-2025
- General
- Yahoo
The Milky Way may not collide with neighboring galaxy Andromeda after all: 'From near-certainty to a coin flip'
When you buy through links on our articles, Future and its syndication partners may earn a commission. A titanic cosmic collision between the Milky Way and its closest large galactic neighbor, Andromeda, may not be as sure a thing as scientists thought. Previously, it had been proposed that there was a good chance that Andromeda and our galactic home, which are moving together, would meet in around 5 billion years and merge to form a daughter galaxy dubbed "Milkomeda." New research has revealed that there is a much smaller chance that these two spiral galaxies will slam into each other and merge over the next 10 billion years than was believed. In fact, it's about 50/50. "Our main finding is that the merger between the Milky Way and Andromeda, which had been predicted to occur in around 4.5 billion years, is actually much less certain. We found only about a 50% chance that this merger will happen during the next 10 billion years," team leader and University of Helsinki researcher Til Sawala told "In short, the probability went from near-certainty to a coin flip. "I was prepared to find something different, but yes, the fact that there is only around a 50/50 chance of a merger was very surprising." Sawala and colleagues reached this conclusion by simulating the next 10 billion years of the Milky Way's journey through the new simulation was based on updated astronomical data from the Hubble Space Telescope and from the European Space Agency (ESA) star tracking mission Gaia. The team also factored in new estimates of the masses of smaller dwarf galaxies around the Milky Way, which, via their gravitational influence, impact the cosmic passage of the Milky Way. "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, including the effect of the Large Magellanic Cloud, the Milky Way's largest satellite galaxy," Sawala said. The team was able to present different scenarios of what could become of the Milky Way and Andromeda galaxies as they gradually move together."A head-on collision is very unlikely, we found a less than 2% chance for that. In most of the cases that lead to a merger, the two galaxies will indeed fly past each other at first, which will lead to a loss of orbital energy, and subsequently to a merger," Sawala said. "How close they come on their first passage is very uncertain, however, and if they don't come very close, meaning if their distance is more than around 500,000 light-years, they might not merge at all." The researchers found that if the orbits of the Milky Way and Andromeda come close enough for the two galaxies to gravitationally influence each other, then a merger is an eventuality. "But it's almost equally likely that they stay well separated, in which case they won't merge, and also continue to evolve mostly in isolation," The team found that while the odds of a merger with Andromeda drop when the Large Magellanic Cloud's influence is considered, with this adjustment, the Milky Way becomes more likely to cannibalize this satellite dwarf to this research, our galaxy is almost certain to merge with the Large Magellanic Cloud over the next 2 billion years. Related Stories: — Why do dwarf galaxies line up? 'Zippers' and 'twisters' in the early universe may solve a galactic mystery — Scientists calculate when the universe will end — it's sooner than expected — Amateur astrophotographer captures a stunning galaxy 24 million light-years from Earth (photo) "Of course, now we really want to find out whether the Milky Way and Andromeda will collide or not," Sawala said. "That will not only need more observational data, but also more complete modelling of their interaction, as well as of the effect of the environment in which they evolve. "Luckily, there will be more observational data coming very soon, next year, from the Gaia Space Telescope, and perhaps also from the Hubble Space Telescope." The team's research was published on Monday (June 2) in the journal Nature Astronomy.
