There is a website that might tell you how you're going to die. It's constantly updated with various potential causes of your death, and their odds. I don't visit this website regularly, which might sound surprising at first—wouldn't you think I'd want to know this?—but the website is superfluous. If one if the items on the list causes your death, it's likely to cause the deaths of many, most, or all other humans on Earth. Once we get to that point, I figure it'll be on the news or something.
The site is Sentry, an automated prediction system run by NASA's JPL. It lists near-Earth asteroids, and their chances of hitting us, and projects the damage they would do. It offers a helpful 10-point scale to tell us how worried we should be. As of this week, there's a new asteroid atop the leaderboard, rated a 3.
2024 YR4 is 27 million miles away. It is about 196 feet wide, and there is, based on the limited observational data so far, a 1.2 percent chance of it hitting the Earth on or around Dec. 22, 2032. There is no reason to get stressed about this. The asteroid is one of about 21,000 Apollo-type asteroids whose orbits cross Earth's. But space is very big, and even with crossing orbits, impacts are rare.
2024 YR4 was only discovered last month, and when we first spot an object, we don't know where it's been so there's no way to tell where it's going. Only subsequent observations can reveal its trajectory. This happens all the time. Five different asteroids were flagged as potential impactors last year, and all five were quickly determined by additional observations to be no threat. 2024 YR4 has been imaged nearly every day since its discovery, narrowing its future path—but still in a relatively wide band. Most likely, further observations will reveal that it's bound to miss us completely.
"People should absolutely not worry about this yet," asteroid hunter David Rankin told Space.com. "Impact probability is still very low, and the most likely outcome will be a close approaching rock that misses us."
The Torino Scale is a useful shorthand for how much you should sweat any given space rock. It combines a near-Earth object's odds of an impact with its size and composition. The further right on the chart you go, the more likely an impact; higher up, more damage if it does strike.
Since the Torino Scale was adopted in 1999, the highest any asteroid has rated is a 4. That was Apophis, an asteroid measuring 1,480 by 560 feet, which when discovered in December 2004 was given a 2.7 percent probability of hitting Earth in 2029. It only took four days for observations to downgrade that possibility and bump it down to a 1 on the Torino Scale, and subsequently a zero.
2024 YR4, as of Monday's observation, was upgraded to a 3 on the Torino Scale, which is where it currently sits. A 3 means relatively low odds of impact, and only localized damage. Still, even localized damage would be significant.
It's possible to retroactively determine where impact events would have rated on the Torino Scale, had they been observed before striking. The Chelyabinsk meteor, which exploded over Russia in 2013, would've been a pathetic zero—it wasn't large enough to warrant concern about damage. The Chicxulub impactor, which is believed to have caused the extinction of the dinosaurs, would've been a 10. Do not poopoo a 3 rating, however. Both the Tunguska Event and Arizona's Meteor Crater were likely caused by objects that would have been rated 8—which, if you'll refer to your handy Torino chart, means they were about the same size as 2024 YR4. On the very small chance this newest asteroid hits, you do not want to be underneath it when it does.
Still, don't spend any time getting nervous about this. Almost certainly, within a few days 2024 YR4 will be downgraded and you will never hear about it again. I'm offering a money-back guarantee on this: If 2032 rolls around and you get smashed into a fine powder by 2024 YR4, we'll refund your Defector subscription.
