Latest news with #Harvard&SmithsonianCenterforAstrophysics
Yahoo
4 days ago
- General
- Yahoo
Astrophysicists Discovered Strange New Objects in Our Galaxy ‘Unlike Anything Else'
Here's what you'll learn when you read this story: The Central Molecular Zone, spanning 700 light-years across the heart of the galaxy, contains a majority of the dense gas in the Milky Way. While analyzing this region with the Atacama Large Millimeter/submillimeter Array (ALMA), an international team of scientists discovered a slew of strange "slim filaments" unassociated with star-forming regions. The filaments are likely part of what the researchers call "space tornadoes," which distributes material throughout the CMZ efficiently. It's been little more than half a century since scientists first proposed that a supermassive black hole lies at the heart of the Milky Way. And in the decades since, we've discovered a remarkable amount about our particular corner of the universe—but there's always more to learn. One area that remains a particular mystery is the Central Molecular Zone, or CMZ, which stretches some 700 light-years across at the heart of the galaxy. This region contains roughly 80 percent of all dense gas in the Milky Way, which—according to the Harvard & Smithsonian Center for Astrophysics—accounts for about tens of millions of solar masses of material. Home to giant molecular clouds and numerous star-forming clusters, the CMZ is a swirling mystery, and there is no other place in the galaxy like it. Now, a new study—led by a team of astrophysicists drawing upon data from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile—is adding another curiosity to this already head-scratching region of the galaxy: unexpected 'slim filaments' that have left astronomers guessing at their origin. Details of this surprising discovery were published in the journal Astronomy & Astrophysics. An array of 66 radio telescopes located under the remarkably clear skies of the Chajnantor Plateau in the Atacama Desert, ALMA (as its name suggests) is particularly well suited to examining the CMZ thanks to its high angular resolution and its ability to trace certain molecules found in abundance in this region of space. Among those molecules is silicon oxide (SiO), which serves as a tracer for shockwaves in the CMZ. By tracing the spectral lines of SiO, astronomers can better understand this chaotic environment—and, as it turns out, discover previously unknown filament structures. 'SiO is currently the only molecule that exclusively traces shocks, and the SiO 5-4 rotational transition is only detectable in shocked regions that have both relatively high densities and high temperatures,' Kai Yang, lead author of the study from Shanghai Jiao Tong University, said in a press statement. 'This makes it a particularly valuable tool for tracing shock-induced processes in the dense regions of the CMZ. When we checked the ALMA images showing the outflows, we noticed these long and narrow filaments spatially offset from any star-forming regions. Unlike any objects we know, these filaments really surprised us. Since then, we have been pondering what they are.' Using the SiO emission lines (along with those of eight other molecules), the astronomers confirmed that their velocities were inconsistent with outflows, show no association with dust emission, and are in hydrostatic equilibrium—a delicate balance between gravity and pressure. All these anomalous findings, packaged alongside insights like 'unlike any objects we know, ' inspire fantasies of massive alien structures hiding out in the heart of our galaxy. But the astronomers have a more science-based explanation, and it is no less mesmerizing. 'We can envision these as space tornados: they are violent streams of gas, they dissipate shortly, and they distribute materials into the environment efficiently,' Xing Lu, a co-author of the study from Shanghai Astronomical Observatory, said in a press statement. 'Our research contributes to the fascinating Galactic Center landscape by uncovering these slim filaments as an important part of material circulation.' The authors theorize that these filaments may be part of a depletion-replenishment cycle at the heart of our galaxy. First, shock waves create these filaments. Then, as these filaments dissipate, they 'refuel' shock-released material in the CMZ and freeze back into dust grains. As scientists delve deeper into the mysteries of these filaments—and if they're as widespread as this particular ALMA sample would suggest—then we may have uncovered an important cyclic process that lies at the heart of our galaxy. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
Yahoo
09-05-2025
- Science
- Yahoo
A half-ton Soviet-era spacecraft stuck in orbit for 53 years is expected to make an uncontrolled plunge back to Earth any day now.
A Soviet-era spacecraft launched in the 1970s is expected to make its return to Earth sometime this weekend. The unmanned robotic spacecraft, Kosmos 482, originally set out to land on the scorching surface of Venus but it never completed its mission. Instead, it's been stuck in Earth's orbit for over 50 years. After all this time, the half-ton object, about the size of a concert grand piano or a male polar bear, is finally expected to make an uncontrolled plunge back to Earth. The problem is, experts aren't exactly sure when — or where — it will land. (Yikes.) Yahoo News spoke with Jonathan McDowell, an astronomer at the Harvard & Smithsonian Center for Astrophysics, about what we do know about the object and whether we should be worried. His responses below have been lightly edited for length and clarity. McDowell: It was originally meant to be the Soviet probe, Venus 9 [that would travel to the surface of Venus]. They launched it in March 1972, along with Venus 8. The rockets put their space probes in parking orbit around the Earth, and then fired the upper stages to send them out toward Venus. Venus 8 got to Venus. But the upper stage for Venus 9 broke down halfway through its rocket firing, stranding the probe in orbit around the Earth. Rather than admit that they'd had a failure, the Soviet Union said 'Oh, we just launched another Kosmos satellite. It's totally fine. We're calling it Kosmos 482. Nothing to see here.' That is like their standard practice. They're now up to Kosmos 2500-something. They throw all their military satellites in there, but also their failures that they don't want to admit. There were a few pieces [of Kosmos 482] left in orbit. There was the rocket stage, there was the main part of the Venus probe, and there was this half-ton sphere that was meant to be the thing that would enter Venus's atmosphere and survive to the surface. Every time these things go around the Earth, they skim the atmosphere and lose a little bit of energy. So they don't go quite so high up the next time. The orbit shrinks over time until eventually the [objects] reenter. Two of the [three] objects reentered in the early 1980s, and there was this one object left that didn't seem to be affected as much by Earth's atmosphere. After 50 years of this going around the Earth every few hours, it has lost enough energy for its orbit to shrink enough that now it's on the verge of reentry. Sometime over the weekend, it's going to get low enough that it can no longer orbit and the atmosphere is too dense. It will slow down rapidly and crash onto the Earth. After 50 years, the batteries are stone cold so there's no way the parachutes will work. [The object weighs] half a ton. It's traveling at 17,000 miles an hour, just like everything else in low Earth orbit. But once it reenters, you'll see this big fireball, and that is the speed energy getting converted into heat energy. The heat shield may protect it from burning up and melting during reentry. It can't fly through the air at 17,000 miles an hour. As it gets dense enough in the atmosphere, [the object] slows down really rapidly because of this enormous headwind. That speed gets converted into heat, and everything slows down. Once it crashes down to the lower atmosphere, it'll only be going at a couple-hundred miles an hour. Somewhere between London in the north and the Falkland Islands in the south (off the east coast of Argentina in the South Atlantic Ocean). So somewhere between 52 degrees north and 52 degrees south. If you're in Scotland or northern Canada or Antarctica, it's not going to come over you. Pretty much anywhere else is still in the frame. Until we can know exactly when it's coming down, we won't know where because if you're an hour off, you're 17,000 miles wrong. This is always true with uncontrolled satellite reentries. We never know where they're going to come down until after the fact. Because the Earth is a big target, the chances that it's going to come down near you is tiny. Most of the Earth is ocean, but maybe we'll be unlucky and it'll hit land. Even today, most land is unoccupied, so the chance that it will hit a person is very small. It's not zero, but it's small. I think any one satellite reentry hitting someone is super unlikely, but we're having so many of them now that we're kind of rolling the dice each time, and eventually we're going to get unlucky. We get about three a day. Most of them are small enough that they melt entirely, burn up and don't reach the ground. Every month or so we get a couple that are going to leave something reaching the ground. Usually they fall over the ocean. Every few months, we get a case where we found a bit on the ground that's from the satellite reentry. What's unusual about this object is that it's designed to survive Venus, which has utterly hellish conditions. It was over-designed for surviving a reentry into Earth's atmosphere. Mind you, it's been in space for over 50 years, so whether the heat shield is still pristine or not, is unclear. Normally what happens is the satellite will melt, even if it doesn't completely burn up, and it will break into chunks. Even if they survive to the ground, they'll be strewn over several hundred miles of reentry track. So there's not much in any one place. But for this [Kosmos 482 object], it's going to come down in one half-ton lump, most likely. So that'd be bad if there's anyone underneath. One thing that's important to know about is the liability convention, which is part of space law. Suppose this crashes into some building in the U.S., or into your garden shed. What do you do? The U.S. government talks to the Russian government and says, 'We have a bit of your space debris under the liability convention. You're entitled to have it back, but you're also liable for any damage that it caused.'
Yahoo
09-05-2025
- Science
- Yahoo
A half-ton Soviet-era spacecraft stuck in orbit for 53 years is expected to make an uncontrolled plunge back to Earth any day now.
A Soviet-era spacecraft launched in the 1970s is expected to make its return to Earth sometime this weekend. The unmanned robotic spacecraft, Kosmos 482, originally set out to land on the scorching surface of Venus but it never completed its mission. Instead, it's been stuck in Earth's orbit for over 50 years. After all this time, the half-ton object, about the size of a concert grand piano or a male polar bear, is finally expected to make an uncontrolled plunge back to Earth. The problem is, experts aren't exactly sure when — or where — it will land. (Yikes.) Yahoo News spoke with Jonathan McDowell, an astronomer at the Harvard & Smithsonian Center for Astrophysics, about what we do know about the object and whether we should be worried. His responses below have been lightly edited for length and clarity. McDowell: It was originally meant to be the Soviet probe, Venus 9 [that would travel to the surface of Venus]. They launched it in March 1972, along with Venus 8. The rockets put their space probes in parking orbit around the Earth, and then fired the upper stages to send them out toward Venus. Venus 8 got to Venus. But the upper stage for Venus 9 broke down halfway through its rocket firing, stranding the probe in orbit around the Earth. Rather than admit that they'd had a failure, the Soviet Union said 'Oh, we just launched another Kosmos satellite. It's totally fine. We're calling it Kosmos 482. Nothing to see here.' That is like their standard practice. They're now up to Kosmos 2500-something. They throw all their military satellites in there, but also their failures that they don't want to admit. There were a few pieces [of Kosmos 482] left in orbit. There was the rocket stage, there was the main part of the Venus probe, and there was this half-ton sphere that was meant to be the thing that would enter Venus's atmosphere and survive to the surface. Every time these things go around the Earth, they skim the atmosphere and lose a little bit of energy. So they don't go quite so high up the next time. The orbit shrinks over time until eventually the [objects] reenter. Two of the [three] objects reentered in the early 1980s, and there was this one object left that didn't seem to be affected as much by Earth's atmosphere. After 50 years of this going around the Earth every few hours, it has lost enough energy for its orbit to shrink enough that now it's on the verge of reentry. Sometime over the weekend, it's going to get low enough that it can no longer orbit and the atmosphere is too dense. It will slow down rapidly and crash onto the Earth. After 50 years, the batteries are stone cold so there's no way the parachutes will work. [The object weighs] half a ton. It's traveling at 17,000 miles an hour, just like everything else in low Earth orbit. But once it reenters, you'll see this big fireball, and that is the speed energy getting converted into heat energy. The heat shield may protect it from burning up and melting during reentry. It can't fly through the air at 17,000 miles an hour. As it gets dense enough in the atmosphere, [the object] slows down really rapidly because of this enormous headwind. That speed gets converted into heat, and everything slows down. Once it crashes down to the lower atmosphere, it'll only be going at a couple-hundred miles an hour. Somewhere between London in the north and the Falkland Islands in the south (off the east coast of Argentina in the South Atlantic Ocean). So somewhere between 52 degrees north and 52 degrees south. If you're in Scotland or northern Canada or Antarctica, it's not going to come over you. Pretty much anywhere else is still in the frame. Until we can know exactly when it's coming down, we won't know where because if you're an hour off, you're 17,000 miles wrong. This is always true with uncontrolled satellite reentries. We never know where they're going to come down until after the fact. Because the Earth is a big target, the chances that it's going to come down near you is tiny. Most of the Earth is ocean, but maybe we'll be unlucky and it'll hit land. Even today, most land is unoccupied, so the chance that it will hit a person is very small. It's not zero, but it's small. I think any one satellite reentry hitting someone is super unlikely, but we're having so many of them now that we're kind of rolling the dice each time, and eventually we're going to get unlucky. We get about three a day. Most of them are small enough that they melt entirely, burn up and don't reach the ground. Every month or so we get a couple that are going to leave something reaching the ground. Usually they fall over the ocean. Every few months, we get a case where we found a bit on the ground that's from the satellite reentry. What's unusual about this object is that it's designed to survive Venus, which has utterly hellish conditions. It was over-designed for surviving a reentry into Earth's atmosphere. Mind you, it's been in space for over 50 years, so whether the heat shield is still pristine or not, is unclear. Normally what happens is the satellite will melt, even if it doesn't completely burn up, and it will break into chunks. Even if they survive to the ground, they'll be strewn over several hundred miles of reentry track. So there's not much in any one place. But for this [Kosmos 482 object], it's going to come down in one half-ton lump, most likely. So that'd be bad if there's anyone underneath. One thing that's important to know about is the liability convention, which is part of space law. Suppose this crashes into some building in the U.S., or into your garden shed. What do you do? The U.S. government talks to the Russian government and says, 'We have a bit of your space debris under the liability convention. You're entitled to have it back, but you're also liable for any damage that it caused.'
Yahoo
05-05-2025
- Science
- Yahoo
53-Year-Old Soviet Spacecraft to Perform 'Final Death Plunge'
After decades of inadvertently orbiting Earth, Kosmos 482 is ready to come home. Astronomers believe the Soviet-era spacecraft is ready to perform its "final death plunge," which will most likely occur this weekend. Kosmos 482 will either disintegrate upon atmospheric reentry or smack into Earth's surface—and one renowned astrophysicist is anticipating the latter. The Soviet Union launched Kosmos 482 on March 31, 1972. At the time, the spacecraft was part of the Venera program, which aimed to place multiple probes in Venus's atmosphere and on its surface. While many Venera probes succeeded, the one launched that day did not: Its escape stage exploded as it attempted to achieve a Venus transfer trajectory, causing the spacecraft to break apart. Some of its fragments decayed within 48 hours, causing space debris to fall onto New Zealand. But the lander probe survived. Back then, it was tradition to attach "Kosmos" to the name of any Soviet spacecraft that achieved Earth orbit, accidentally or not; as a result, the failed Venera probe became Kosmos 482. It's circled our planet ever since, starting as high as 6,000 miles and gradually sinking down to its current maximum of 245 miles above Earth's surface. Now, the 1,092-pound hunk of metal is preparing to re-enter the planet's atmosphere, according to computer models tracking Kosmos 482's slow descent. "It's in its final death plunge," Jonathan McDowell, an astronomer at the Harvard & Smithsonian Center for Astrophysics, said on NPR's All Things Considered. The meter-wide Kosmos 482 lander probe. Credit: NASA McDowell tracks satellite and space debris, sharing the juiciest of his findings via social media. Many times, these objects aerosolize upon reentry; on occasion, they survive the trip. Since Kosmos 482 was originally designed to withstand Venus's atmosphere, McDowell thinks this particular spacecraft could be a survivor. "What I expect is instead of burning up and melting, it will reenter essentially undamaged," McDowell told NPR. "And so somewhere on Earth, this half ton sphere will fall out of the sky at a couple hundred miles an hour. And most likely it'll be over the ocean, and no one will ever know….There's a not trivial chance that it could hit somewhere where it damages property. And there's a small chance—but it's like one in thousands—that it could hurt somebody." Marco Langbroek, a spy satellite researcher at the Dutch satellite tracking station SatTrackCam Leiden, co-developed a reentry model that places Kosmos 482's potential landing anywhere between Canada, Russia, and the southern end of South America—a vast swath of Earth that doesn't afford many global citizens much comfort. But even this blurry geographical window might not be accurate. "The reentry is an uncontrolled reentry," Langbroek notes. "At the moment, we cannot say with any degree of certainty when and where the Kosmos 482 Descent Craft exactly will reenter."
Yahoo
14-02-2025
- Science
- Yahoo
A Supermassive Black Hole Is on a Collision Course With The Milky Way
A Milky Way collision with a supermassive black hole might be closer than we thought. Hidden deep in the Large Magellanic Cloud dwarf galaxy that orbits the Milky Way on an ever-closing loop, signs of a massive invisible object clocking in at around 600,000 times the mass of the Sun have been detected. Since the Large Magellanic Cloud will one day collide with our own galaxy, that means the black hole is also destined to come crashing in. What's even more interesting is that the black hole falls into a mass regime rarely seen, under a million times the mass of the Sun. If its existence can be confirmed, it gives us a new datapoint for understanding how black holes grow from star-sized masses to chunky monsters equivalent to not just millions but billions of Suns' worth of mass. The discovery, led by astrophysicist Jiwon Jesse Han of the Harvard & Smithsonian Center for Astrophysics (CfA), has been submitted to The Astrophysical Journal, and is currently available on preprint server arXiv. Black holes can actually be pretty difficult to spot. Unless they're actively slurping up matter, a process that produces blazing light as the material is super-heated by friction and gravity, they emit no radiation we can detect. That means scientists have to get tricky, and one of their tricks is to look for stars that are moving around in a way that can be explained no other way. The primary method of doing this is to measure for unusual orbits. It was by carefully studying orbits in the center of the Milky Way, for example, that astronomers confirmed the existence and mass of Sagittarius A*, the supermassive black hole at the center of the Milky Way (it's about 4.3 million solar masses, if you're interested). Han and his colleagues did not look for orbits, however. Instead, their research focused on another type of stellar motion: the hypervelocity star, anomalous objects that travel much faster than the average speed of other stars in their galaxy – so fast, they could even make a break for intergalactic space. There are a number of these daredevil stars zooming through the galactic halo, destination unknown. The way these stars are accelerated led the researchers to the notion that they might lead us to hidden black holes. That acceleration kick is known as the Hills mechanism, a three-body interaction between a black hole and two stars. Eventually, the gravitational dance will lead to a member of this triplet being forcefully yeeted across space at hypervelocity. The recently retired Gaia space telescope spent several years in space mapping the objects of the Milky Way, including their positions in three-dimensional space (which is harder than you'd think), as well as their motions and velocities. Armed with Gaia data, the researchers made a new analysis of 21 hypervelocity stars in the galaxy's outer halo that are consistent with the Hills mechanism. These stars are all of the B subtype, huge and hot, with relatively short lives, which means their high-speed journeys through space have to have been relatively short too. This analysis involved tracking back the stars' velocity and motion to their point of origin, carefully ruling our other possible acceleration scenarios. They were able to confidently trace 16 stars. Seven of them originated close to Sgr A*, at the center of the Milky Way. The remaining nine stars, however, appear to have come from the Large Magellanic Cloud. And together, they suggest ejection via the Hills Mechanism by an object that weighs around 600,000 solar masses – a hidden black hole lurking therein. The Large Magellanic Cloud currently orbits the Milky Way at a distance of around 160,000 light-years. Its long, slow fall into our galaxy is not a straightforward affair, but an ongoing dance; a recent estimate puts the encounter at around 2 billion years away. Once the two galaxies are merged, the supermassive hole in the Large Magellanic Cloud – if black hole there is – will make its way to the galactic center, where it will eventually, after many more eons, merge with Sgr A* to make an even bigger black hole. Astronomers believe that this is one way that black holes can grow from relatively small sizes to even bigger ones. It would be so incredible to see that process slowly taking place, right here in our own galaxy – even if we're not going to be around to see the finale. Future research, the team hopes, will help them confirm the existence and determine the properties of their fascinating new discovery. The research, submitted to The Astrophysical Journal, is available on arXiv. Astronomers Discover Nearby Alien World That May Sustain Life NASA Announces Return Date For Astronauts Trapped on ISS Record-Breaking Neutrino From Deep Space Spotted by Undersea Telescope
