Latest news with #Tunguska
ABC News
3 days ago
- General
- ABC News
Meet the NASA scientist tasked with identifying asteroids on a collision course with Earth
The bright green meteor that blazed a trail over the skies of southern WA earlier this month served as a spectacular reminder of just how vulnerable the Earth is to threats from space. Country police officer and amateur meteorite hunter Marcus Scott found a tennis ball sized piece of the space rock, dubbed the Mother's Day meteorite, in a salt lake about 460 kilometres east of Perth. Hollywood has taught us to fear giant 'planet killer' asteroids, but it's the smaller space rocks that could destroy an entire city. Thankfully, a NASA scientist is on the case, with the job of protecting the planet against such threats. Dr Kelly Fast oversees NASA's Planetary Defense Coordination Office, which is responsible for identifying and tracking asteroids, and figuring out if any of these rocky bodies could be on a collision course with Earth. Larger meteors can survive the trip through the atmosphere, often in spectacular fashion, like the Mother's Day meteorite which was estimated to be about half a metre in size. It slammed into the atmosphere above WA travelling at about 15 kilometres a second, before breaking up and landing in a salt lake in the Goldfields. Dr Fast and her colleagues around the world track more than 37,000 near-Earth asteroids, with the US Congress expecting NASA to find 90 per cent of asteroids larger than 140 metres. It's the smaller asteroids that pose the danger because they are harder to find, but could still destroy a land mass the size of an Australian city or even a state. "The asteroid hazard is a global issue. The first order of business is finding asteroids… it's the only natural disaster that you could potentially prevent," she said. Last year an asteroid named 2024 YR4 was discovered, with initial calculations indicating it could come dangerously close to Earth in just seven years' time. With a diameter of approximately 50 metres, if it struck the earth it could cause widespread devastation of a similar scale to the Tunguska event in Siberia in 1908. That explosion occurred over a sparsely populated area, flattening more than 2,000 square kilometres of forest. Dr Fast said there were a few different forms of technology that could potentially be used to neutralise the threat from an asteroid, and they all sound like they are straight out of a science fiction movie. The Double Asteroid Redirection Test (DART) spacecraft slammed into the asteroid Dimorphous in September 2022, successfully changing the orbit of the 160-metre diameter celestial body. "That was the simplest technique — to impact an asteroid and change its speed, and it was successfully tested with DART," Dr Fast said. To date, it's been the only real world test to save the planet from destruction caused by a rogue space rock. Other techniques being studied include ion beam deflection, using a spacecraft to fire charged particles at the asteroid, giving it a slight nudge to change its orbit. The 'Star Trek' sounding "gravity tractor" is another possible solution, and entails parking an object next to the asteroid and using the slight change in gravity to change its orbit. "And then there's what we always like to call the Hollywood option, because it's what's always used in the movies — a nuclear deflection," Dr Fast said. Although she warned such a technique could create even more of a hazard from the debris field of an exploded asteroid. Dr Fast is hoping there won't be a need to use any of these techniques in our lifetime, but says developing the technology to protect the planet will be a gift for future generations. This week Dr Fast spoke at the Australian Space Awards in Sydney, where she emphasised Australia's importance in keeping the planet safe from the threat of asteroids. And while Australia might be half a world away from NASA headquarters in Washington D.C., two teams of Australian researchers form part of the International Asteroid Warning Network. The University of New South Wales Canberra team search for asteroids using optical telescopes as well as the Parkes Radio Telescope, famous for its role in broadcasting Neil Armstrong's moon walk. On the other side of the country, researchers at the University of Western Australia use the one-metre diameter Zadko Telescope, located about 70 kilometres north of Perth in Gingin, to scan the skies for threats from space. Hollywood-born Dr Fast has a degree in astrophysics and a doctorate in astronomy. She also has the honour of having a nearly three-kilometre diameter space rock named after her, Asteroid Kellyfast. "Like pretty much all asteroids that are named for people, let's hope it stays safely out in the main belt [of space]" she said with a laugh.
Yahoo
03-04-2025
- Science
- Yahoo
NASA catches a glimpse of 'city-killer' asteroid before it disappears until 2028
Astronomers have gotten a glimpse of the "city-killer" asteroid before it disappears until 2028, according to NASA. The space rock, called 2024 YR4, was previously given up to a 3.1% chance of striking Earth in December 2032, but astronomers have since eliminated the possibility of a strike at that time based on further observations. MORE: 3.5 billion-year-old crater created by meteorite impact found in Australia, scientists say Astronomers are watching 2024 YR4 closely, trying to learn everything they can before it disappears from view by mid-April, Kelly Fast, a planetary defense officer at NASA, told ABC News earlier this year. Its unique elongated orbit takes the asteroid around the sun and into Earth's vicinity before it ventures far out between the orbits of Mars and Jupiter and out of sight, Fast said. NASA's Center for Near Earth Object Studies used the James Webb Space Telescope -- the largest, most powerful telescope ever launched into space -- to capture photos of the asteroid, the space agency announced on Wednesday. New infrared observations indicate that the asteroid measures between 174 feet and 220 feet in diameter -- about the size of the 10-story building, according to NASA. While it is not forecast to strike Earth in 2032, the asteroid now has a 1.7% probability of hitting the moon at that time, the space agency said. The space rock was first discovered on Dec. 27 by astronomers monitoring the ATLAS telescope at the University of Hawaii, Fast said. MORE: Chance of asteroid striking Earth in the next decade rises to 3.1%, NASA says In the past, even when the asteroid passed through the inner solar system, it didn't always come close to where Earth was at the time, which is why it was only recently discovered, Fast said. The asteroid has been dubbed a "city-killer" due to its size and potential to cause major destruction. It is large enough to cause localized damage were it to strike a populated city, Fast said. In 1908, the similarly sized Tunguska asteroid flattened trees over an area of about 1,250 miles after it exploded in the skies over Siberia. NASA has been tasked by Congress with locating asteroids larger than 450 feet in length, which are large enough to do "regional" damage in the event of a strike, Fast said. MORE: There's a small chance an asteroid could hit Earth within the next decade, says NASA The asteroid currently has a 1.1% chance of striking Earth on Dec. 22, 2047, according to NASA. More than a 2% chance of an asteroid strike is "uncommon," Davide Farnocchia, a navigation engineer with NASA's Jet Propulsion Laboratory, told ABC News in February. But astronomers will continue to monitor the asteroid closely. "We don't want to take any chances," Farnocchia said. NASA catches a glimpse of 'city-killer' asteroid before it disappears until 2028 originally appeared on
Yahoo
02-04-2025
- Science
- Yahoo
'City-Killer' Asteroid Impact Still a Possibility (Just Not With Earth)
Just when you thought you could relax about putative 'city killer' asteroid 2024 YR4, back it comes, with a vengeance. Don't worry – it's still not a danger to Earth for the time being. When we last checked in, odds of a collision between 2024 YR4 and Earth were at just 0.001 percent, far too low to be considered potentially hazardous, and that's where it remains. So we're in the clear. That's great. The Moon, though? The Moon might still be in the asteroid firing line. According to a report led by planetary astronomer Andrew Rivkin of Johns Hopkins University, 2024 YR4 has a small chance of smacking into the Moon when the asteroid next flies close to Earth in December 2032. "While an Earth impact by 2024 YR4 on December 22, 2032 has now been ruled out," the researchers wrote in a preliminary report, "it continues to have a non-zero probability of impacting the Moon at this time." What does this mean? At the moment, we don't really know. Further JWST observations of the rock are planned for May 2025; hopefully they will help narrow down the odds of a collision with the Moon, and the potential effect – if any – it would have on Earth. In a more comprehensive report published in the Research Notes of the AAS, the researchers laid out the full details of their observations. The asteroid was only discovered for the first time on 27 December 2024, and rapidly rang alarm bells. Its projected trajectory around the Sun brought it close enough to Earth to pose a hazard; at their highest, estimates of an impact in 2032 rose to 3.1 percent, which may not seem very high, but it's high enough to pose a huge problem. Continued observations and furious calculations restored normalcy, dropping the odds down to practically zero, and everyone breathed a huge sigh of relief. However, we still need to know more about the asteroid; it's going to continue to fly past Earth as it flies around the Sun, and we need as much observational data as possible to predict its ongoing course. As YR4 receded and grew fainter, scientists recruited JWST to take measurements. According to a measure of light reflecting off 2024 YR4, Rivkin and his colleagues determined that the asteroid is about 60 meters (197 feet) across. This is consistent with previous measurements, and confirms that the asteroid is large enough to be a significant danger if it were going to hit us. JWST also measured a range of wavelengths emitted by 2024 YR4 that could be used to determine how reflective it is. While we can't be certain, the analysis could not rule out an asteroid with a rocky composition. If this is the case, the researchers calculated, an impact with Earth would release energy between 2 and 30 megatons of TNT, creating a blast radius up to 80 kilometers. The most powerful nuclear bomb tested by the US, for context, released 15 megatons of energy; and the Tunguska event, a meteor airburst that flattened a Siberian forest, is thought to have released about 15 megatons also. Luckily, we don't have to fret about any of this for Earth from YR4 for now. Nevertheless, we haven't heard the last from YR4. In addition to the planned observation in May, another observation opportunity is going to arrive in 2026, allowing scientists to further narrow down its orbit and composition. Fingers crossed that it's going to be good news for the Moon. The report has been published in the Research Notes of the AAS. Parker Probe Repeats Record Brush With The Sun in Daredevil Dive Moon's Shadows Could Harbor Microbes. Here's Why That's A Concern. Einstein Didn't Think This Stunning Picture Was Possible. We're Glad He Was Wrong.
Yahoo
18-03-2025
- Science
- Yahoo
Killer space rocks
When you buy through links on our articles, Future and its syndication partners may earn a commission. It was from a football field–size asteroid designated 2024 YR4. Detected in December by a telescope in Chile, the space rock was flagged for its size—it's 130 to 300 feet long, big enough to wipe out a city—and a trajectory that put it on track to possibly hit Earth on Dec. 22, 2032. NASA initially put the chance of an impact at 1.2 percent. The odds soon jumped to 3.1 percent, or 1 in 32, a record high for an asteroid of its size. But after closer study of the asteroid's orbit, the threat of a hit was downgraded to a negligible 0.004 percent. While humanity's plans for the 2032 holidays are safe, the scare highlighted a threat that scientists say urgently needs more focus: the millions of giant rocks that are hurtling through space, some of which may be on collision courses with our planet. 'Take it as a warning shot across our bow,' said astrophysicist Neil DeGrasse Tyson. 'These things are out there.' NASA's Center for Near Earth Object Studies (CNEOS) tracks more than 37,000 asteroids whose trajectories approach Earth's orbit. Most are the size of a car or smaller and pose no risk, because they will burn up in our atmosphere. On the opposite end of the spectrum are 'planet killers': asteroids a kilometer or more across that could potentially wipe out civilization. About 900 have been identified. In between are a range of potential threats. A 160-foot-wide asteroid could destroy a major metropolitan area; those are thought to strike once every 1,000 years. A 500-foot- wide space rock could inflict mass casualties across a state or a small country; those arrive every 20,000 years. Of course, 'these numbers are very approximate,' said planetary geologist Gordon Osinski, 'and they don't really help us figure out when the next one might happen.' On Feb. 15, 2013, a roughly 60-foot-wide asteroid entered the atmosphere and exploded 19 miles above the Russian city of Chelyabinsk. It set off a blinding flash and a shock wave that damaged more than 7,000 buildings over 200 square miles, and injured more than 1,600 people, many of them hit by shattered glass. The light from the blast was like 'the end of the world,' said Valentina Nikolayeva, a teacher. In 1908, a 130-foot-wide asteroid or comet—the latter is an icy ball of dust and rock—exploded 6 miles above a remote stretch of Siberia, releasing 185 times more energy than the atomic bomb dropped on Hiroshima. Some 800 square miles of forest were leveled in the so-called Tunguska event. Still, that space rock was a pebble compared with the one that wiped out the dinosaurs 66 million years ago. There's no current fear of anything of that magnitude hitting Earth, but other Tunguska-size threats are out there. Possibly. But first we have to see them coming. In 2005, Congress directed NASA to find and track, by 2020, 90 percent of near-Earth objects—asteroids or comets that come within 30 million miles of our planet's orbit— 460 feet or larger. Right now 'we're at something like 45 percent,' said CNEOS director Paul Chodas. NASA has built a network of telescopes, including the one in Chile that detected 2024 YR4, to identify threats. An infrared space telescope, NEO Surveyor, that will further boost detection is scheduled for launch in 2027. When a new object is found, information is shared with a global web of space agencies and observatories that go to work determining its shape, size, and orbital path. If one is judged to be headed for Earth, the next task is to try to alter its path—something NASA recently proved feasible. In 2022, it launched the golf cart–size Double Asteroid Redirection Test (DART) spacecraft, which slammed into Dimorphos, a 530- foot asteroid, at 14,000 miles per hour. The collision successfully altered the projectile's orbit. Researchers are also studying the use of a 'gravitational tractor,' a spacecraft that would orbit alongside an asteroid, exerting gravitational pull that would gradually alter the rock's course. All these efforts require years of advance planning and may not be effective against a giant asteroid. If a space rock is too large for deflection—or due to hit with relatively short notice— humanity would need to use a nuclear bomb to deflect or vaporize it. A 2021 study showed that a 1-megaton nuke launched at least two months before impact could annihilate a 330-foot asteroid. But setting off a nuke in space is no small matter. It 'could be very awkward geopolitically,' said Robin George Andrews, author of How to Kill an Asteroid. It's just one example of how asteroid response requires a globally coordinated effort. We're making progress. The Chelyabinsk explosion led to the creation of NASA's Planetary Defense Coordination Office, designed in part to link efforts with other groups such as the U.N.-sponsored International Asteroid Warning Network. And last year for the first time, international representatives attended NASA's biennial Planetary Defense Interagency Tabletop Exercise, which gamed out the discovery of a massive asteroid with a 72 percent chance of impacting Earth in 2038. Scientists say this cooperation is a step in the right direction, but that many questions remain around a potential global asteroid defense. What's the best approach? Who would be in charge? 'Asteroid impacts are one of the few natural disasters that we actually have the means to both foresee and prevent,' said NASA aerospace engineer Brent Barbee. We must be 'as prepared as possible.' Some 66 million years ago, an asteroid at least 6 miles wide slammed into Mexico's Yucatan Peninsula. Digging a crater 125 miles wide, it triggered earthquakes and tsunamis, and firestorms that may have spanned the globe. Gas, soot, and dust blanketed the planet, blotting out the sun and sending global temperatures plummeting. That extinction event wiped out 75 percent of life on Earth—including the dinosaurs. But some experts believe the impact would have been far less calamitous if the rock had landed elsewhere. A 2017 study concluded that the asteroid struck a spot unusually rich in organic sediment, which worsened the blackout effect. The dinosaurs might have survived if not for that happenstance, the researchers believe, and the rise of the mammals—including humans— might never have occurred. 'This is maybe a lucky coincidence that everything came into place like it is today,' said geochemist Mario Fischer-Gödde.
The Guardian
22-02-2025
- Science
- The Guardian
The Observer view: when an asteroid is hurtling to Earth, do you head for the pub or the church?
Following the possible trajectory of 2024 YR4 – AKA the scariest asteroid ever detected – is not for the nervous of disposition. Is it going to hit us, or not? Every day, a different answer. Last Tuesday, Nasa calculated it had a 3.1% chance of hitting Earth in 2032, and so some people set to worrying. Twenty-four hours later, however, the agency provided an update. New observations, made since the passing of the full moon, show it now has a 1.5% chance of impact. Time to exhale? Not necessarily. The asteroid is estimated to be 40-90 metres wide, about the same size as a large building. If it does hit, and doesn't splash down into the sea, it could decimate a city. Scientists calculate that its impact could be similar to that of the Tunguska asteroid, which flattened an area more than double the size of New York in Siberian forest in 1908. If it landed in central London, windows 20 miles away in Slough would be broken – an event that would exceed the wildest dreams even of John Betjeman, who once wrote a rather mean poem about the town. How to feel about this lump of rock hurtling towards us at 38,000mph? To pinch from The Simpsons Movie, is it the pub or the church for you? (Faced with catastrophe, the patrons of Moe's Tavern run from bar to church, while the congregation of the latter sprints in the opposite direction, desperate for a stiff drink.) Most of us will keep calm and carry on, whatever the percentages. Seven years is a long time: you'll be a size 10 by then – that, or getting divorced. The key thing about Armageddon is that it's always in the future, as the followers of myriad cults have found to their cost down the years. Let us trust the experts – remember them? – to sort it out. A few years ago, Nasa significantly changed the orbit of an asteroid. The Dart spacecraft slammed into a 150-metre asteroid moon at speed, changing its orbital period by more than 30 minutes – a result that could be replicated, if planning began now. A few, should the predictions get worse, may go full survivalist, filling their bunkers with tinned carrots. But their number will be small. The news cycle is hardly relaxing at the moment, the old order as frangible as digestive biscuits. A person has the capacity for only so much terror, and now may not be the time to start worrying what will happen to Birmingham if YR4 turns out to be West Midlands-bound. The year 1998 came with its share of global calamities, but the notion of a world war seemed far away compared with today, which may be one reason why two big films about asteroids then played to packed cinemas. In Deep Impact, a comet on a collision course with Earth hits, causing a tsunami that destroys the US east coast, a mission by the Messiah spacecraft having failed to alter its path. In Armageddon, a rogue asteroid is broken into fragments by a nuclear bomb that is somehow inserted into it by, among others, an oil driller played by Bruce Willis – though it's not all good news: Shanghai is obliterated by another meteor strike along the way. No prizes for guessing which film did better at the box office. Sign up to Observed Analysis and opinion on the week's news and culture brought to you by the best Observer writers after newsletter promotion Hope springs eternal, though we all know perfectly well that no one gets out of here alive.
