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Yahoo
19-02-2025
- Science
- Yahoo
Key facts about asteroid that could hit Earth in 2032
An asteroid capable of flattening a mid-sized city could potentially collide with Earth eight years from now, as its orbit around the sun briefly intersects the path of our planet. Named 2024 YR4, the space rock carries with it very slim odds of striking land — either on Earth or, even less likely, the moon — and astronomers recently set the odds of a crash at 3.1%. International space organizations like NASA are taking the possible threat seriously, however small it might be. Richard Moissl, the head of the European Space Agency's Planetary Defence Office, said their attentiveness shouldn't unduly raise public concern. He shared key facts about the asteroid with CBS News during the below conversation, which has been edited for clarity. When would the asteroid hit Earth? This asteroid passes us by every four years. Every time we go four times around the sun, it has almost precisely completed one turn. It has just recently had a flyby in December 2024, which means the next flyby is in December 2028, and we know already that this one is no problem. The critical one is in 2032, on the 22nd of December, somewhere around the middle of the day in Universal Time. That is when the asteroid is passing, really, through a part of the orbit of the Earth. So, it's really going through the path of Earth, so to speak. And the question is, whether Earth will be there at this point in time, or whether it will have already passed or is still approaching that point. It's the question, where will it pass by? There's an uncertainty region that spans, right now, the entire Earth-Moon system — which is not to say that we don't know a lot about it. In fact, we know a lot about it. Now, we're looking at a closing moment in time on the 22nd of December, 2032, and the question is about fractions of a meter per second, which will make all the difference. There's about a 20-something-minute window in which the Earth can be in the way of this before it's no longer in the path of the asteroid, or the asteroid cannot come in contact with the Earth anymore. How is the asteroid risk being managed? Until recently, we did daily measurements with different telescopes. Then, we had to pause a little bit for one or two days because of the full moon, and the object being too close to the full moon, and the moon illuminating the sky too much to see it. From now on, we will not monitor it daily, but it will be constantly monitored in the best way possible, with ever larger telescopes. And the idea is to measure its path around the sun in ever higher positions, so you will see this uncertainty region shrink, and shrink, and shrink. And we are trying to constrain the uncertainty so much that we can say whether it passes by Earth safely, or whether there is still some chance left in the middle of April. What happens in April? We will be so far away from the object that we cannot observe it from Earth anymore. And then, the James Webb Telescope will take measurements. It will actually take one in March, primarily infrared observations that give us more insight about the size of the object, and then one more in May to do additional measurements. The most likely scenario is that, by that time, you will be able to say, look, we can prove it's not going to hit Earth, but there is a chance that we cannot eliminate it completely. And that will be the more interesting bit, because then we have to wait until mid-2028, when we can observe it again. We will not let that time pass by without action. When was the last time an asteroid had similar odds of hitting Earth? This is only the second time that impact prediction systems have rated any asteroid with an impact probability of more than 1%. The last time was about 20 years ago, with the asteroid Apophis in 2004, which reached a couple of percent for a brief period in time before the uncertainty region could be constrained. That shows how unusual 1% is, and that means that we, as experts, have to take this seriously. However, with the current probability estimated at around 3%, it's still around 97% likely that nothing bad will happen at all. So, that needs to be kept in mind all the time. This is something that merits attention, but it's not perceived as an imminent threat. It's just, we need to find out more about it. Have asteroids this size actually crashed into Earth? We are aware of a recent example in history where this has happened. It was 1908 in Siberia. There was an event where 2,000 square kilometers of forest had been flattened by a big explosion, high up in the atmosphere. And this is very consistent with a body about 50 meters in diameter, plus or minus 10 meters, entering Earth's atmosphere. The body itself was, then, likely not a solid piece of rock. It was more like, what we call a pile of smaller pieces of rock. And this burst several kilometers above the surface and had this effect, that 2,000 square kilometers of forest was flattened, that seismic waves went out from this and could be detected far away, that people witnessed this event, also from very far away. We don't know if anyone was hurt in that accident. Nothing is reported. But the size, the footprint of the destruction is comparable to a major urban area, or a big city on Earth. So, this is basically the scenario that we would expect from this. Another example not recorded in human history was an object believed to have been about 50 meters in diameter, a massive chunk of iron that formed the Barringer meteor crater in Arizona. It's a 1.2-kilometer crater. If you look at this and think about it, if that were to hit in a city, the city would look very, very different afterward. The estimated size of this asteroid ranges from about 40 to 90 meters. Wouldn't there also be a big difference between the damage caused by something 40 meters wide versus 90 meters? Absolutely. I mean, the 40 to 90 meters is a standard estimate, because we cannot know at this point in time what the surface brightness is. Current data indicate it's more toward the 40- or 50-meter size. So, luckily, on the smaller size range, which is why I cited these popular examples for this. But, indeed, size matters for asteroids. Size matters a lot. If we're talking about the doubling of the radius of an asteroid, that means eight times the mass, eight times the energy, and that is a significant difference, of course. While on the lower end of the scale, with about 40 meters, it would be threatening to, let's say, a middle-sized city, on the 90-meter edge, it might be comparable to the biggest urban areas. Why has the probability of 2024 YR4 hitting Earth increased since it was first discovered? The good news is, this increase does not mean that the asteroid has become more dangerous. The path of the asteroid is defined by physical laws. It's already clear. It's just our knowledge of where that path would be, in reality, is not perfect yet. The percentage can be compared to the size of the uncertainty area, compared with the size of the Earth. If you look at the fraction, the size of the Earth — which is inside the uncertainty area — is compared to the entire area of the uncertainty of where the asteroid could be in that critical moment in time. This equated to about 1% when we reached this threshold for international awareness. Since then, the size of the uncertainty region has basically shrunk by half. And the size of Earth, luckily, remains the same. So, that means Earth is now occupying twice the amount of space in the uncertainty region. And it means our estimate for the impact risk has risen from 1% to 3%. It doesn't mean that anything has changed. Again, 3% is a 97% chance of missing. So what will happen is, with our gaining knowledge, uncertainty will shrink further and further and further, and the expected case is that we will manage to shrink it so much that Earth is no longer inside this uncertainty region, and then the impact probability will drop to zero. In the case of this being a close flyby to Earth, if it's reasonably close, it's entirely possible that the impact probability will continue to rise a little bit on a modest path. This is still no cause for alarm. The asteroid has been assigned a Level 3 ranking, out of 10, on the Torino Impact Hazard Scale. How uncommon is that? It's the first time ever that an object is officially classified as a Level 3 on the Torino scale. The only other object that was ever classified with a level higher than 1 was Apophis. Because of its larger size, Apophis has been classified as a 4 on the Torino scale, which is really just indicating that it's a larger object. [Apophis has an estimated diameter of 350 meters, which is much larger than the asteroid 2024 YR4.] What else should people know? Well, the most important thing is, don't panic. Always good advice, but it's definitely applicable advice in this situation. I think this gives us a chance to prove that we, as a planet, can still rise above things on Earth that are between people, between countries, between parts of Earth. That if we are facing a completely outside threat, that we can all come together, join forces and face these kinds of threats together. This one is a manageable challenge. Even if it were to be headed towards Earth, which is by no means certain, 97% it's clear that it will miss us. So, not much to be afraid of, but a good chance to show that we can stand united on this planet. Trump administration fires thousands of U.S. Forest and National Park Service workers DOGE "receipts" show approved spending, not evidence of fraud Millions of Americans under extreme cold warnings
Yahoo
16-02-2025
- Science
- Yahoo
James Webb telescope to study asteroid that could hit Earth in 2032
STORY: The James Webb Space Telescope - launched to study things like the formation of the earliest galaxies - is going to be used to learn everything we can about this: asteroid '2024 YR4.' :: ESA The asteroid has an approximately 98% chance of safely passing Earth on December 22, 2032, according to recent data. :: ESA But while Juan Luis Cano at the European Space Agency's Planetary Defence Office says people should not be too concerned about the possibility of an impact… He says astronomers need more data. :: Juan Luis Cano, Planetary Defence Office 'This is a warning for us as scientists and researchers that we should put a lot of attention on this subject..." That's where the James Webb telescope comes in. The asteroid was first recognized as a potential threat in December 2024. It's density and composition is currently unknown... But it's estimated to be between 131 and 295 feet across and traveling about 15 times the speed of a high-velocity bullet. The James Webb Space Telescope will be brought in to get a more precise estimate of the asteroid's size and to study the heat it emits, rather than the visible light it reflects. This method can provide a more accurate size estimation - crucial for assessing the asteroid's potential hazard. :: ESA The first round of observations from Webb will take place in early March, and the second round in May. With those details, there's a good chance the risk of impact could be eliminated, Cano said. 'So this is good news because in nine of ten cases, we will be able to remove these objects from the risk list. However, this is still a 10% probability that this object will remain in the list after May, in which case we would only be able to see it again in the spring of 2028 and only then we would know whether it would be an impact trajectory or not with it.' :: File If the asteroid's impact probability remains above the 1% threshold even after the Webb observations, scientists will discuss Earth's response. That could include crashing a spacecraft into it to deflect it off course, a technique successfully demonstrated by NASA's DART spacecraft in 2022. Asked about a worst-case scenario, Cano references the 1908 Tunguska event over Siberia that leveled 830 square miles of trees. He said if YR4 were to be about 295 feet: "...We would easily be speaking of ten times the effect of Tunguska, of the Tunguska event."
The Independent
10-02-2025
- Science
- The Independent
Nasa using world's most powerful telescope to examine asteroid that could smash into Earth
Scientists will point the world's most powerful telescope at the asteroid 2024 YR4, in the hope of understanding whether it might pose a threat to Earth. The space rock was found late last last year but the threat of a collision was recently doubled after scientists discovered more information about its route around the solar system. The chances are still very low: today, there is a roughly 98 per cent chance that it will sail harmlessly past Earth. It is also thought to be relatively small, so that the impact of any collision is likely to be local to wherever it lands. But astronomers are keen to better understand that risk, in case any precautions need to be taken to keep the Earth safe. That work is happening against the clock because the asteroid will fade from view in a few months' time, and is not expected to come back until 2028. If the asteroid is really coming towards us, then space agencies might need to launch defensive measures before then. Scientists will now use the James Webb Space Telescope – jointly operated by Nasa and the European and Canadian space agencies – to examine the rock with the hope of better understanding its orbit. Scientists hope not only to improve their estimates of where the asteroid will go, but also its nature. The potential danger posed by the rock will vary dramatically based on how large it is. At the moment, scientists estimate that it is somewhere between 40 and 90 metres across, largely in line with their calculations since it was first discovered in December 2024. That estimate is based largely on how much light it reflects from the Sun – but that can be altered considerably by how reflective the rock is. The Webb telescope is able to look at the infrared light or heat that is emitted from the asteroid, which provides a much better estimate of its size. The first set of observations will happen in early March when the asteroid will become visible to Webb and will be at its brightest point. Astronomers will be able to use that information to refine their understanding of the rock before it disappears again, ready for it to become visible once more in 2028. Webb spends much of its time looking much deeper into the universe, in the hope of understanding its structure and answering more fundamental questions. But some time is set aside for 'Director's Discretionary Time', and astronomers including those from the European Space Agency 's Planetary Defence Office proposed using it for the asteroid, and were given four hours to do so.
