Transcript of Scientists warn there’s 1 in 50 chance of Asteroid 2024 YR4 striking Earth | BBC News

Now, an asteroid that was spotted late last year by space scientists is being carefully tracked. Scientists are trying to work out whether there's a chance of it hitting the Earth, which could happen eight years from now. Our science editor, Rebecca Morrell, is here with more details. Rebecca.

Thanks, Jane. Well, there's still a lot we need to learn about asteroid 2024 YR4. What we do know is that it's estimated to be between 40 and 90 meters, and the date it could hit is the 22nd of December, 2032. Now, that chance is very small. It was thought to be 1. 3%, but that risk has now gone up to 2%, but scientists say, don't panic.

We talk about collision risks with these things a lot, but maybe it's better to think about the avoidance risk or the avoidance probability, and that's actually still quite high. There's a 98% chance that this object will not hit our planet. So maybe that's what we should keep in mind.

That increase in impact risk is something that astronomers expect, and here's why. When an asteroid is first spotted, we're still learning about its orbit. The asteroid could pass through anywhere in this red zone. It's called the area of uncertainty, and it's big. Now, the Earth is in it, too, but the risk of a collision is low. As we get more information, the area of uncertainty of where the asteroid might be shrinks. But now you can see that the Earth pulls up more of it, so the risk increases. But as we learn even more, the area of uncertainty shrinks further, hopefully to a point where the Earth is now outside of it, so there's a zero risk of a collision. Astronomers are now trying to find out as much as they can, but time is short. The asteroid is currently moving away from the Earth, and after May, it won't be visible again until 2028. So they're using the most powerful tool they have, the James Webb Space Telescope. This This will tell astronomers the precise size of the asteroid and more about its orbit. It's crucial information should we need a plan of action.

Although we may not be certain that at the moment this asteroid is going to hit, if it is going to hit, we know exactly when that will occur. We know what we need to do, for example, if we just want to evacuate an impact area, or in fact, if we have enough warning time, as may be the case for this one, we can actually mount a deflection mission.

Nasa has already tested a deflection mission. It crashed a spacecraft into another small asteroid and successfully changed its orbit. But don't worry, we're not at that stage yet. Astronomers will continue to monitor this space rock.