Latest news with #Bernardinelli-Bernstein
Yahoo
26-06-2025
- Science
- Yahoo
A Gigantic Megacomet Is Erupting as It Zooms through the Solar System
There's a giant ball of ice barreling through the solar system right now, and it's bigger than any we've seen before. It poses no threat to Earth, but this comet, called C/2014 UN271 (Bernardinelli-Bernstein), has enraptured astronomers ever since its discovery in 2021. The hulking object, sometimes jovially called a 'megacomet,' is 100 times bigger than most comets we see in the solar system. And now we're learning more about it than ever before as it zooms toward its closest approach to our sun in 2031. In a study published in the Astrophysical Journal Letters on June 12, Nathan Roth of American University and his colleagues report the first conclusive detection of carbon monoxide on the megacomet. That's a crucial finding because it might tell us more about the object's origins, history and likely upcoming behavior as it dives deeper into the solar system. 'We wanted to test what drives activity in this comet,' Roth says. 'It's so far from the sun and so cold that trying to explain what makes a comet 'work' at these distances is difficult.' C/2014 UN271 was first imaged by chance in observations from 2014. Seven years later, when astronomers actually spotted it in their archives, the comet was at more than 20 times the Earth-sun distance, inside the orbit of Neptune. But they also found that it is on a path that will bring it nearly to Saturn's orbit in 2031 before it heads out again. The comet's orbit is huge, extending out to about 55,000 times the Earth-sun distance—87 percent of a light-year and well out into the Oort Cloud of icy objects that surrounds our sun. [Sign up for Today in Science, a free daily newsletter] Following the comet's discovery astronomers used various telescopes, including the James Webb Space Telescope and the Hubble Space Telescope, to scrutinize it from afar. The object was initially thought to be as big as 370 kilometers (230 miles) across. Revised observations showed it to be about 140 kilometers (87 miles) wide. But that's still the biggest anyone has ever seen—most comets in the solar system are only one or two kilometers across. 'It's huge,' says Quanzhi Ye, an astronomer at the University of Maryland, who was not involved in Roth's study. 'It represents a part of the cometary spectrum that we don't understand.' Some of those observations revealed bursts of activity from the comet, which sprouted an enormous, enveloping 'coma' of expelled gas that stretches some 250,000 kilometers (155,000 miles) across (more than half the distance from the Earth to the moon). To find out the cause of this activity, Roth and his team used the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to observe the comet in radio waves for about eight hours in March 2024. They found a clear trace of carbon monoxide spewing from the comet, suggesting that its sprawling coma is fueled, at least in part, by carbon monoxide ice sublimating—turning from solid to gas—as the comet approaches the sun. The carbon monoxide appears to be vented in jets from spots on the object's surface, possibly the result of the overhead sun heating a localized region and causing the ice to sublimate. 'If you were standing on the comet, and the sun was right overhead, this is the area where the sun is heating the surface the most and the jet originates from,' Roth says. What's not clear so far, however, is how fast the comet is spinning and whether the location of the jets is changing over time. 'Are there different jets being activated at different times? We don't know yet,' Roth says. As C/2014 UN271 gets closer, other ices that are often found on comets, such as methane and hydrogen sulfide ice, might start to sublimate, too, and add their own contributions to the object's activity. 'As we continue to monitor it, we'll be able to get a better idea of the chemical fingerprint that's preserved inside the comet,' Roth says. Rosita Kokotanekova, an astronomer at the Rozhen National Astronomical Observatory in Bulgaria, who was not part of Roth's research team, says the detection of carbon monoxide is useful because it is 'important to identify what prompts activity at these large distances.' Researchers have witnessed gas venting from other, much smaller comets at a similar distance, 'which was very puzzling,' she adds. 'People were trying to figure out what exactly is causing this activity [so far from the sun].' C/2014 UN271's size makes it an especially alluring target for study. The presence of carbon monoxide ice is doubly interesting: Analysis of available data about the comet revealed that it first exhibited signs of activity at more than 25 times the Earth-sun distance. But according to theoretical models, its carbon monoxide ice should have been sublimated by the sun's rays when the object was even farther out in the solar system. This discrepancy may mean the comet made a pass of the sun before, with sublimation first eating away at layers of ice on its surface and its current activity only being kickstarted at closer distances, when heat from sunlight reached ice deeper within the object. Finding a behemoth like C/2014 UN271, Kokotanekova says, could hint at the existence of a whole class of gigantic progenitor comets. Such comets might have been the first large, icy objects to coalesce in the solar system, after which they could have eventually broken apart to form smaller comets. 'It's possible that the small objects are mostly fragments, while the large ones, like UN271, have never collided with anything,' she says. That might mean there are more primordial megacomets awaiting discovery. If so, the recently completed Vera C. Rubin Observatory in Chile, which will begin a 10-year panoramic survey of the heavens later this year, could find more of them. 'It's so sensitive that it will certainly pick up comets of this size, quite probably even further away from us,' Ye says. Rubin's wide eye on the sky should also give us more information on C/2014 UN271 itself, says Meg Schwamb, an astronomer at Queen's University Belfast uninvolved with this latest finding. 'Rubin's going to watch it come in,' she says. That could help us get a better handle on its activity, in partnership with telescopes like ALMA. 'You need both of those pieces of information—if it got brighter, and whether the amount of carbon monoxide changed—to tell you what's going on,' Schwamb says. For now Comet UN271 remains a fascinating target of study, a giant comet like no other that is giving us a unique window into the dark frontiers of the outer solar system. 'This is just an incredibly exciting object,' Roth says. And, for astronomers eager to learn more about this and other mega comets, the best is yet to come.
Scientific American
26-06-2025
- Science
- Scientific American
Astronomers Spy Jets Spewing from Megacomet Zooming through the Solar System
There's a giant ball of ice barreling through the solar system right now, and it's bigger than any we've seen before. It poses no threat to Earth, but this comet, called C/2014 UN271 (Bernardinelli-Bernstein), has enraptured astronomers ever since its discovery in 2021. The hulking object, sometimes jovially called a 'megacomet,' is 100 times bigger than most comets we see in the solar system. And now we're learning more about it than ever before as it zooms toward its closest approach to our sun in 2031. In a study published in the Astrophysical Journal Letters on June 12, Nathan Roth of American University and his colleagues report the first conclusive detection of carbon monoxide on the megacomet. That's a crucial finding because it might tell us more about the object's origins, history and likely upcoming behavior as it dives deeper into the solar system. 'We wanted to test what drives activity in this comet,' Roth says. 'It's so far from the sun and so cold that trying to explain what makes a comet 'work' at these distances is difficult.' C/2014 UN271 was first imaged by chance in observations from 2014. Seven years later, when astronomers actually spotted it in their archives, the comet was at more than 20 times the Earth-sun distance, inside the orbit of Neptune. But they also found that it is on a path that will bring it nearly to Saturn's orbit in 2031 before it heads out again. The comet's orbit is huge, extending out to about 55,000 times the Earth-sun distance—87 percent of a light-year and well out into the Oort Cloud of icy objects that surrounds our sun. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Following the comet's discovery astronomers used various telescopes, including the James Webb Space Telescope and the Hubble Space Telescope, to scrutinize it from afar. The object was initially thought to be as big as 370 kilometers (230 miles) across. Revised observations showed it to be about 140 kilometers (87 miles) wide. But that's still the biggest anyone has ever seen—most comets in the solar system are only one or two kilometers across. 'It's huge,' says Quanzhi Ye, an astronomer at the University of Maryland, who was not involved in Roth's study. 'It represents a part of the cometary spectrum that we don't understand.' Some of those observations revealed bursts of activity from the comet, which sprouted an enormous, enveloping 'coma' of expelled gas that stretches some 250,000 kilometers (155,000 miles) across (more than half the distance from the Earth to the moon). To find out the cause of this activity, Roth and his team used the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to observe the comet in radio waves for about eight hours in March 2024. They found a clear trace of carbon monoxide spewing from the comet, suggesting that its sprawling coma is fueled, at least in part, by carbon monoxide ice sublimating—turning from solid to gas—as the comet approaches the sun. The carbon monoxide appears to be vented in jets from spots on the object's surface, possibly the result of the overhead sun heating a localized region and causing the ice to sublimate. 'If you were standing on the comet, and the sun was right overhead, this is the area where the sun is heating the surface the most and the jet originates from,' Roth says. What's not clear so far, however, is how fast the comet is spinning and whether the location of the jets is changing over time. 'Are there different jets being activated at different times? We don't know yet,' Roth says. As C/2014 UN271 gets closer, other ices that are often found on comets, such as methane and hydrogen sulfide ice, might start to sublimate, too, and add their own contributions to the object's activity. 'As we continue to monitor it, we'll be able to get a better idea of the chemical fingerprint that's preserved inside the comet,' Roth says. Rosita Kokotanekova, an astronomer at the Rozhen National Astronomical Observatory in Bulgaria, who was not part of Roth's research team, says the detection of carbon monoxide is useful because it is 'important to identify what prompts activity at these large distances.' Researchers have witnessed gas venting from other, much smaller comets at a similar distance, 'which was very puzzling,' she adds. 'People were trying to figure out what exactly is causing this activity [so far from the sun].' C/2014 UN271's size makes it an especially alluring target for study. The presence of carbon monoxide ice is doubly interesting: Analysis of available data about the comet revealed that it exhibited signs of activity when it was more than 25 times as far out as the Earth-sun distance. But according to theoretical models, its carbon monoxide ice should have been sublimated by the sun's rays when the object was even farther out in the solar system. This discrepancy may mean the comet made a pass of the sun before, with sublimation first eating away at layers of ice on its surface and its current activity only being kickstarted at closer distances, when heat from sunlight reached ice deeper within the object. Finding a behemoth like C/2014 UN271, Kokotanekova says, could hint at the existence of a whole class of gigantic progenitor comets. Such comets might have been the first large, icy objects to coalesce in the solar system, after which they may could have eventually broken apart to form smaller comets. 'It's possible that the small objects are mostly fragments, while the large ones, like UN271, have never collided with anything,' she says. That might mean there are more primordial megacomets awaiting discovery. If so, the recently completed Vera C. Rubin Observatory in Chile, which will begin a 10-year panoramic survey of the heavens later this year, could find more of them. 'It's so sensitive that it will certainly pick up comets of this size, quite probably even further away from us,' Ye says. Rubin's wide eye on the sky should also give us more information on C/2014 UN271 itself, says Meg Schwamb, an astronomer at Queen's University Belfast uninvolved with this latest finding. 'Rubin's going to watch it come in,' she says. That could help us get a better handle on its activity, in partnership with telescopes like ALMA. 'You need both of those pieces of information—if it got brighter, and whether the amount of carbon monoxide changed—to tell you what's going on,' Schwamb says. For now Comet UN271 remains a fascinating target of study, a giant comet like no other that is giving us a unique window into the dark frontiers of the outer solar system. 'This is just an incredibly exciting object,' Roth says. And, for astronomers eager to learn more about this and other mega comets, the best is yet to come.
Yahoo
25-06-2025
- Science
- Yahoo
Record-Sized Comet Seen Belching Jets From Surface as It Heads Our Way
An absolutely gigantic comet is currently barreling into the inner Solar System at full steam. And we mean that almost literally – astronomers have now detected big outbursts of carbon monoxide belching from its surface. Comet C/2014 UN271 (Bernardinelli-Bernstein) is the largest Oort Cloud comet ever detected, spanning a whopping 137 kilometers (85 miles) wide. For reference, that's almost 14 times bigger than the asteroid that wiped out the dinosaurs. It's a little unsettling that something that big is currently hurtling in our direction, but thankfully it won't come any closer than the orbit of Saturn, when it reaches its closest approach on 29 January 2031. Astronomers have now observed the comet using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, confirming its monster size and spotting molecular activity. "These measurements give us a look at how this enormous, icy world works," says astrochemist Nathan Roth of American University and NASA Goddard Space Flight Center. "We're seeing explosive outgassing patterns that raise new questions about how this comet will evolve as it continues its journey toward the inner Solar System." ALMA observed the comet UN271 on 8 and 17 March 2024, shortly after it gave off an outburst. As such, the first observation showed more activity than the second, as the comet settled back down. Related: On March 8, ALMA spotted a pair of jets blasting out of the comet's nucleus – its solid icy core. Spectrometry revealed that these jets were mostly made of carbon monoxide. The team also detected the beginnings of a coma, the 'atmosphere' of dust and gas that surrounds comets and forms their tails. By the March 17 observation, however, the comet was down to a single jet, although the team speculates that the other could have just rotated out of view. There was also no longer any sign of the coma. Although previous observations had noted hints of a coma before, this marks the first direct detection of the jets of gas coming out of UN271. Even more impressive is that they were spotted so far away – at the time, the comet was just inside the orbit of Uranus, some 16 times the distance between Earth and the Sun. Previous estimates placed the size of UN271's nucleus at around 137 kilometers across, making it comfortably the largest comet ever seen coming out of the huge bubble of icy objects surrounding the outer Solar System known as the Oort Cloud. It's more than twice the estimated size of the previous record-holder, comet Hale-Bopp. That said, it's not the largest known comet of any type. That honor belongs to 95P/Chiron, which could be more than 210 kilometers wide. Thankfully it doesn't journey in and out of the Solar System but sticks to a stable orbit around the Sun between Saturn and Uranus. As UN271 zooms closer, astronomers will no doubt continue to study it over the next few years. It should put on a pretty spectacular show, albeit one that will have to be enjoyed through telescopes – sadly, it won't get close enough to be visible from Earth with the naked eye. The research was published in The Astrophysical Journal Letters. Behold! World's Largest Camera Snaps Millions of Galaxies in First Pics 2032 'City-Killer' Impact Threatens Earth's Satellites, Study Finds Check It Out! Rubin Observatory Reveals First Glimpses of Stunning Space Images
