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Yahoo
a day ago
- General
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There's a 50/50 Chance the Milky Way and Andromeda Galaxy Will Merge
The universe might not meet its end for another quinvigintillion years, but our galaxy's fate teeters on a far less certain line. New research shows that there's a 50% chance that the Milky Way and its nearest major galactic neighbor, the Andromeda Galaxy, will converge within the next 10 billion years. Previous analyses have made out the convergence to be a sure-fire thing, but it turns out that one dwarf galaxy is recalibrating the scales. Though about 2.5 million light-years currently lie between the Milky Way and Andromeda, the two galaxies are creeping closer to each other. In 1913, astronomer Vesto Melvin Slipher noticed via Arizona's Lowell Observatory that Andromeda (then known as the Andromeda Nebula) was approaching the Milky Way at 186 miles per second. Since then, researchers have not only verified Slipher's math but also found via multiple simulations that Andromeda will someday combine with the Milky Way. One paper from 2021 even proposes that the two galaxies will meet 4.3 billion years from now, with a complete merger taking another 6 billion years after that. But these simulations failed to account for one small yet mighty factor: the Large Magellanic Cloud. Roughly 160,000 light-years from our Milky Way, this dwarf galaxy has long been considered an insignificant part of the so-called Local Group. But in 2015, the beginning of the Survey of the MAgellanic Stellar History, or SMASH, found that the Large Magellanic Cloud was larger and more complex than initially thought. Astronomers have spent the years since sifting through SMASH data for dwarf galaxy secrets. Illustration of a hypothetical merger between the Milky Way and Andromeda Galaxy. Credit: NASA, ESA, STScI, DSS, Till Sawala (University of Helsinki); Image Processing: Joseph DePasquale (STScI) It's for this reason that the latest Milky Way-Andromeda merger simulation actually includes the Large Magellanic Cloud. To cover for every possible uncertainty, an international team of astronomers ran their simulation nearly 100,000 times and found that just under 50% of the time, the Milky Way and Andromeda collided and merged. Alternately dropping different nearby galaxies showed that Messier 33 (the third largest galaxy in the Local Group) made a merger more likely, while the Large Magellanic Cloud reduced the odds of a convergence. That's because the Large Magellanic Cloud pulls the Milky Way out of Andromeda's path, as a comic book hero would pull a civilian off some train tracks. The Large Magellanic Cloud might only get to bask in its glory for a few hundred million years, however. The researchers' simulation showed that the Milky Way will almost certainly collide with the Large Magellanic Cloud in 2 billion years, disappearing the latter galaxy. As observatories gather more data about the universe—and scientists' models inevitably become more advanced—we'll find out whether the Large Magellanic Cloud really will swoop in to save the day. Of course, we won't see the benefit either way. But it will be nice to know whether our galactic home will continue to exist after we're gone.
National Geographic
2 days ago
- Science
- National Geographic
There's now a 50-50 chance this galaxy will crash into ours
Researchers have long thought that the Milky Way would collide with the Andromeda galaxy in four to five billion. In this scientific illustration of the Earth's horizon four billion years in the future. After its first close pass, Andromeda is tidally stretched out following its first close pass by the Milky Way, which is also warped. Illustration by NASA, ESA, Z. Levay and R. van der Marel (STScI), and A. Mellinger For more than a century, astronomers have watched the Andromeda galaxy, a massive swirl of neighboring stars, speed toward the Milky Way. And in recent years, measurements using the Hubble Space Telescope seemed to confirm a long-held prophecy: In about four or five billion years' time, the two galaxies will clash, ultimately merging into a colossal and unrecognizable new galaxy. A fresh survey of both galaxies and—crucially—several of the other weighty galaxies in the same corner of the cosmos has now cast doubt on that calamitous outcome. The new forecast looked billions of years into the future and found that the odds of an Andromeda and Milky Way merger is about fifty-fifty. 'A coin flip is the more accurate description,' says Till Sawala, an astrophysicist at the University of Helsinki and a co-author of the new study. A messy galactic apocalypse is no longer a guarantee. As noted in the team's new study, published today in the journal Nature Astronomy, 'proclamations of the impending demise of our galaxy seem greatly exaggerated.' Earth won't be around in five billion years' time; it'll likely be scorched and swallowed up by our expanding, dying Sun. But if the Milky Way and Andromeda galaxies successfully swerve around one another, that's good news for future worlds. A merger on this scale often sees the supermassive black holes at their hearts of each galaxy unify and expand into a fearsome, hyper-energetic astrophysical monster. That prevents nearby gas cooling down and gathering up to form new stars—and without new stars, you won't get new planets. The possibility of a galactic near-miss is 'somehow comforting,' says Alister Graham, a galaxy researcher at the Swinburne University of Technology in Australia and who wasn't involved with the new research. It's nice to think the Milky Way 'still has a long, planet-forming future ahead of it.' This animation depicts the collision between our Milky Way galaxy and the Andromeda galaxy, which will merge into a single galaxy. The video also shows the Triangulum galaxy, which will join in the collision and perhaps later merge with the "Milkomeda" galaxy. NASA, ESA, and F. Summers (STScI) Galaxy merger mayhem Astronomers witness galaxy mergers happening throughout all of space and time. Two similarly massive galaxies uniting is referred to as a major merger, whereas if a larger galaxy ingests a smaller one, it's known as a minor merger. Although some stars get torn apart by the extreme gravitational interactions of the two galaxies churning about—and some, including their planets, will be scattered like confetti in all directions—but the spaces between individual stars are so vast that most of them don't collide. And although the smaller galaxies can vanish into the maws of the larger ones, the result is often constructive. 'Minor mergers deliver both stars and gas—the raw material for future star formation—into the host galaxy. The stellar winds from newly formed stars enrich the interstellar medium with dust and metals, further fueling the star formation cycle,' says Graham. Even the Milky Way shows evidence of having been assembled via multiple galactic smash-ups. 'Up to 50 percent of the mass in galaxies today come from previous galaxies cannibalized,' says Christopher Conselice, an extragalactic astronomer at the University of Manchester in England and who wasn't involved with the new research. Andromeda is visible to the naked eye from Earth. Here it can be seen as a bright spot in the night sky rises above Tufa formations in Mono Lake, California. Photograph by Babak Tafreshi, Nat Geo Image Collection At 2.5 million light-years away, Andromeda, also known as M31, is our closest large galactic neighbor. Photograph by ESA/NASA/JPL-Caltech/GBT/WSRT/IRAM/C. Clark (STScI) Though astronomers have known that Andromeda is careening toward the Milky Way since the turn of the 20th Century, they weren't sure how direct, or glancing, the clash would be. But in 2012, a landmark study using Hubble came to a definitive conclusion: Based on the motions of their stars, and the galaxies' hefty masses, both would be gravitationally drawn into one another for a head-on collision in four to five billion years. (Later studies have come up with slightly earlier or later timelines for when the merger would happen, but never cast doubt on its inevitability.) And about two billion years after the tempestuous major merger, the two ink-like star spirals would settle down and coalescence. 'It would be an elliptical blob,' says Sawala. Both galaxies can be visible in the night sky: The Milky Way, which stretches across the night sky from the constellations Cassiopeia to Cygnus, and the Andromeda Galaxy appears above this 3000-year old bristlecone pine tree. Photograph by Babak Tafreshi, Nat Geo Image Collection Since 2012, this outcome became gospel among the scientific community, and a textbook fact. 'Should the Milky Way and Andromeda be all that matter—sorry about the pun—then they would be heading straight at each other,' says Graham. But the possibility of a future smash-up depends on the behavior of everything else in our Local Group, too: the panoply of at least 100 galaxies hanging about in this part of the universe. Other big galaxies in our neck of the woods might push or pull on the two voyagers over time. Sawala's team decided to simulate the evolution of the Milky Way and Andromeda galaxies ten billion years into the future. But while doing so, they also accounted for other major players in the Local Group: specifically, the spiral-shaped (and third-largest) Triangulum galaxy and the Large Magellanic Cloud (or LMC), an irregular galaxy that orbits the Milky Way. The team used data from both Hubble and the European Space Agency's stargazing Gaia space observatory to more precisely determine the motions of these galaxies, as well as their masses—comprised of both ordinary matter and the invisible, but more prevalent, dark matter. Although the Triangulum Galaxy was already known to be quite massive, the LMC was thought to be a bit of a lightweight. But the new data suggest that it's surprisingly massive—equivalent to 10 to 20 percent of the mass of the Milky Way. 'And that will have an effect on how the Milky Way moves through space,' says Sawala. The team simulated the motions of these four heavyweight galaxies thousands of times. While the Triangulum galaxy's gravitational influence conspired to bring the Milky Way and Andromeda together, the LMC had a repellent effect. And when all four danced together, the odds of an eventual major merger was just one-in-two. This scientific illustration of the Earth's horizon 3.75 billion years in the future shows Andromeda filling the field of view and the Milky Way beginning to show distortion due to tidal pull from Andromeda. Illustration by NASA, ESA, Z. Levay and R. van der Marel (STScI), T. Hallas, and A. Mellinger A scientific illustration of the Earth's horizon 3.85 to 3.9 billion years in the future shows the first close approach of Andromeda. The sky is ablaze with new star formation, which is evident in a plethora of emission nebulae and open young star clusters. Illustration by NASA, ESA, Z. Levay and R. van der Marel (STScI), T. Hallas, and A. Mellinger 'There are going to be uncertainties in how and when the Milky Way and Andromeda would merge,' says Conselice. Dark matter may act as a binding force. But dark energy, a mysterious force that seems to push everything the universe apart, will also play a role—and recent data suggests it's strength can change over time. That makes forecasting a far-flung galactic merger somewhat tricky. But it's safe to say that it's no longer a certainty that these two galaxies will collide. Some astronomers have suggested that if they do, the new galaxy could be named Milkomeda. That moniker doesn't exactly roll off the tongue. Don't worry, Sawala says: 'We will have billions of years to think of a better name.' Either way, galactic pandemonium will shape the Milky Way's future. Even though the LMC is pushing Andromeda and our own galaxy apart, the team's simulations also show with that, within the next two billion years, the LMC will spiral into us and be gobbled up by a merciless Milky Way. 'It's basically 100 percent that this will happen,' says Sawala. 'There's no escaping that.'
Yahoo
5 days ago
- Science
- Yahoo
Amazing Time Lapse Of Fading Supernova Spied By Hubble
The Hubble Space Telescope captured imagery of supernova 2018 GV from 2018-2019. It was seen in barred spiral galaxy NGC 2525, which is located about 70 million light-years away in the constellation Puppis. Credit: / footage courtesy: NASA, ESA, J. DePasquale (STScI), M. Kornmesser and M. Zamani (ESA/Hubble), A. Riess (STScI/JHU) and the SH0ES team, and the Digitized Sky Survey / produced & edited by Steve Spaleta
Yahoo
16-05-2025
- Science
- Yahoo
Webb captures Jupiter's surprisingly active Northern Lights
A fresh look at Jupiter's powerful auroras with the James Webb Space Telescope has revealed never-before-seen details, and has uncovered a strange mystery for researchers to solve. On Christmas Day in 2023, a team of astronomers aimed the sensitive Webb Telescope at the largest planet in our solar system. Although this had been done before, they had a very specific target in mind — the intense auroras that surround the immense planet's magnetic north pole. While these Jovian Northern Lights had been imaged in the past, using the Hubble Space Telescope, Webb provided them with an unprecedented view, capturing the details of this phenomenon like never before. Jupiter's auroras (left) captured by the James Webb Space Telescope's NIRCam (Near-Infrared Camera) on Dec. 25, 2023. The image on the right shows the planet Jupiter to indicate the location of the observed auroras, which was originally published in 2023. (NASA, ESA, CSA, STScI, Ricardo Hueso (UPV), Imke de Pater (UC Berkeley), Thierry Fouchet (Observatory of Paris), Leigh Fletcher (University of Leicester), Michael H. Wong (UC Berkeley), Joseph DePasquale (STScI), Jonathan Nichols (University of Leicester), Mahdi Zamani (ESA/Webb)) "What a Christmas present it was — it just blew me away!" Jonathan Nichols, the lead researcher of this study from the University of Leicester, said in a NASA press release. Auroras on Earth — the Northern Lights and Southern Lights — occur as high-energy particles from the Sun stream past the planet, either flowing on the solar wind or from massive eruptions of solar matter, known as coronal mass ejections (CMEs), sweeping by us. These particles are captured by our planet's geomagnetic field and funnelled down into the upper atmospehre. There, they collide with atoms and molecules of oxygen and nitrogen in the air, passing on their energy. The energized oxygen and nitrogen then release that energy as coloured flashes of light — greens and reds from oxygen, and mostly blue from nitrogen. The Northern Lights, spotted near Guelph, ON, on September 16, 2024. (Stormhunter Mark Robinson) This same process occurs on Jupiter, but with an additional source of high energy charged particles. While the planet's intense magnetic field captures particles from the solar wind and CMEs, it also picks up ionized particles from the innermost of its four largest moons. Io is the most volcanically active object in the solar system. Hundreds of volcanoes dot its surface, which are powered by the tidal stretching and squeezing induced by the gravitational 'tug-of-war' the moon endures as it orbits the planet and periodically passes by its neighbours, Europa and Ganymede. Io, imaged by NASA's Juno spacecraft during its 57th pass around Jupiter. The combinations of blemished and smooth terrain on the surface is due to nearly constant volcanic activity. (NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill) Jupiter's magnetic field acts like a particle accelerator, driving this combination of solar and volcanic ions down into the planet's upper atmosphere so they hit the atoms and molecules there at tremendous speeds. As a result, Jupiter's auroras glow extremely brightly. Since the process of producing auroras also generates heat, aka infrared light, Jovian auroras show up very brightly to Webb, which is specifically designed to capture that part of the spectrum of light. This allowed the researchers to get a very detailed view of the auroras, and spot how they changed with time. What they saw over the course of their observations surprised them. "We wanted to see how quickly the auroras change, expecting them to fade in and out ponderously, perhaps over a quarter of an hour or so," Nichols explained. "Instead, we observed the whole auroral region fizzing and popping with light, sometimes varying by the second." Three different views of Jupiter's auroras are shown here from Dec. 25, 2023, superimposed on an earlier JWST image of the planet. (NASA, ESA, CSA, STScI, Ricardo Hueso (UPV), Imke de Pater (UC Berkeley), Thierry Fouchet (Observatory of Paris), Leigh Fletcher (University of Leicester), Michael H. Wong (UC Berkeley), Joseph DePasquale (STScI), Jonathan Nichols (University of Leicester), Mahdi Zamani (ESA/Webb)) Jupiter's auroras also produce a rare type of hydrogen known as the trihydrogen cation. Normal hydrogen gas is composed of two hydrogen atoms, thus there are two protons in the nucleus, which are surrounded by two electrons. In a trihydrogen cation, there are three protons surrounded by two electrons, which causes it to be positively charged. It was this very specific molecule that Nichols and his team were able to focus Webb onto, to gather the data for their study. According to NASA, detecting the emissions from these trihydrogen cations will help scientists understand how the upper atmosphere of Jupiter heats and cools. There was one odd thing that Nichols' team noticed in their observations. Auroras show up in various colours across the spectrum of visible light, such as green, red, and blue. However, when we use telescopes to see auroras on Jupiter, we only see them in infrared and ultraviolet wavelengths. In this case, JWST handled the infrared observations, while another telescope provided the ultraviolet view. "What made these observations even more special is that we also took pictures simultaneously in the ultraviolet with NASA's Hubble Space Telescope," Nichols explained. Comparing the images from opposite ends of the spectrum is where a mystery popped up. The assumption was that the brightest regions in both UV and IR light should match up. However, they didn't. "Bizarrely, the brightest light observed by Webb had no real counterpart in Hubble's pictures," Nichols said. "This has left us scratching our heads. In order to cause the combination of brightness seen by both Webb and Hubble, we need to have a combination of high quantities of very low-energy particles hitting the atmosphere, which was previously thought to be impossible. We still don't understand how this happens." The difference might be due to the abundance of particles from the Sun versus the abundance of volcanic particles from Io. Or, there may be something else going on here that they haven't accounted for. According to NASA, the research team plans on delving deeper into their comparison between the Webb and Hubble data they collected. They also plan on making further observations with Webb, which can be compared with data from the Juno spacecraft currently orbiting Jupiter. Click here to view the video
Newsweek
15-05-2025
- Science
- Newsweek
NASA Just Detected Ice in Another Star System for the First Time
Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources. Newsweek AI is in beta. Translations may contain inaccuracies—please refer to the original content. NASA's James Webb Space Telescope has made the first-ever and long-anticipated detection of ice outside of our own solar system. The frozen water was found within a debris disk circling HD 181327, a young, sun-like star that lies some 155 light-years from Earth in the constellation of Telescopium. The ice is paired up with fine dust particles in the disk— forming what has been dubbed "itsy-bitsy dirty snowballs"—with more further out from the star, where it is colder. Astronomers refer to what we would call ice as "water ice," to distinguish it from other frozen molecules such as, for example, carbon dioxide in the form of "dry ice." "Webb unambiguously detected not just water ice, but crystalline water ice," said paper author and astronomer Chen Xie of Johns Hopkins University in Baltimore. Crystalline water ice, Xie explained, is known to be found in various places within our solar systems—from some of the moons of the outer planets to Saturn's rings, comets and other rocks that make up the Kuiper Belt at the edge of the solar system. An artist's impression of the water-ice–bearing debris disk around HD 181327. An artist's impression of the water-ice–bearing debris disk around HD 181327. NASA, ESA, CSA, STScI, Ralf Crawford STScI Astronomers have been waiting for such a definitive detection of water ice elsewhere in the universe for decades, based on the previous detections of water vapor out among the stars, as well as where frozen water ice can be found in our own solar system. "When I was a graduate student 25 years ago, my advisor told me there should be ice in debris disks, but prior to Webb, we didn't have instruments sensitive enough to make these observations," explained paper author and astronomer Christine Chen of the Space Telescope Science Institute, also in Baltimore, in a statement. Webb confirmed the presence of water ice around HD 181327 after hints of such were revealed by NASA's Spitzer Space Telescope back in 2008. Chen added: "What's most striking is that this data looks similar to the telescope's other recent observations of Kuiper Belt objects in our own solar system." In fact, the team said, billions of years ago our Kuiper Belt was likely very similar to the debris disk around HD 181327, when our solar system was similarly young. "HD 181327 is a very active system. There are regular, ongoing collisions in its debris disk," said Chen. "When those icy bodies collide, they release tiny particles of dusty water ice that are perfectly sized for Webb to detect." With this study complete, the researchers will continue to search for other examples of water ice in debris disks and actively forming planetary systems across the Milky Way. "The presence of water ice helps facilitate planet formation," Xie noted. "Icy material may also ultimately be 'delivered' to terrestrial planets that may form over a couple hundred million years in systems like this." The detection of water ice elsewhere in the galaxy, thus, should well pave the way for scientists to study how these processes play out in other planetary systems. Do you have a tip on a science story that Newsweek should be covering? Do you have a question about astronomy? Let us know via science@ Reference Xie, C., Chen, C. H., Lisse, C. M., Hines, D. C., Beck, T., Betti, S. K., Pinilla-Alonso, N., Ingebretsen, C., Worthen, K., Gáspár, A., Wolff, S. G., Bolin, B. T., Pueyo, L., Perrin, M. D., Stansberry, J. A., & Leisenring, J. M. (2025). Water ice in the debris disk around HD 181327. Nature, 641(8063), 608–611.
