Chance of Asteroid Strike in 2032 Drops Sharply After Record-Setting Rise. Here’s Why It Keeps Changing
NASA announced that asteroid 2024 YR4 now has a 0.28 percent chance of hitting Earth in 2032, but that number is expected to continue shifting with further observations
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A space rock briefly set an ominous record this week. On February 18, the impact probability of asteroid 2024 YR4 hitting Earth in late 2032 reached the highest ever documented by NASA for an object of its size or larger: a 3.1 percent chance of a strike.
But that risk level turned out to be short-lived—new observations led the agency to lower that probability back down to 1.5 percent the following day. Then, it dropped further, currently sitting at just 0.28 percent.
“Our understanding of the asteroid’s path improves with every observation. We’ll keep you posted,” NASA wrote Wednesday on X. The new observations come in the wake of a full moon, which was bright enough to temporarily limit astronomers’ ability to continue observing the infamous space rock with ground-based telescopes.
New data gathered last night (Feb. 19-20) dropped the December 2032 impact odds of asteroid 2024 YR4 to 0.28%. Monitoring continues. https://t.co/LuRwg1eaCv https://t.co/O4NnL4PaTf
— NASA (@NASA) February 20, 2025
Originally reported by the NASA-funded Asteroid Terrestrial-impact Last Alert System (ATLAS) station in Chile on December 27, 2024, asteroid 2024 YR4 quickly rose to the top of NASA’s Sentry risk table and the European Space Agency’s near-Earth object Risk List.
Since then, astronomers have revised their predictions of its impact probability as they gather more data. The original “more than 1 percent chance” of impact on December 22, 2032, gradually climbed before the recent drop. Despite the changing probabilities, asteroid 2024 YR4 had remained ranked at level three on NASA’s Torino Impact Hazard Scale, simply meaning it deserved scientific attention—that is, until the latest report. Now, it’s ranked as one, for a near-Earth pass that “poses no unusual level of danger.”
Astronomers had predicted that the impact risk would initially rise before decreasing. The fact that astronomers haven’t been studying asteroid 2024 YR4 for very long is a key contributor to that fluctuation.
“The tiny bit of tracking creates a large uncertainty for where the asteroid will be on any date far into the future,” Richard Binzel, a planetary scientist at MIT and inventor of the Torino Impact Hazard Scale, explains to Forbes’ Jamie Carter. “In 2032, that uncertainty happens to include Earth’s tiny speck in space.”
Binzel uses pasta to explain the uncertainty in the asteroid’s orbit and why the impact probability initially increased. Essentially, the projection of all the places asteroid 2024 YR4 could be on December 22, 2032, looks like a single fettuccine.
“Earth just happens to lay underneath that noodle, and the fraction that the Earth occupies is the probability of impact,” Binzel tells CNN’s Ashley Strickland.
Further observation of the asteroid “shrinks the noodle. As the noodle shrinks, but still happens to include the Earth, it can make the calculated [impact] probability go up,” he adds. “Eventually we will pin down the asteroid’s position to that of a single grain. Most likely that grain will not be on top of the Earth.”
On Wednesday, there was also a slim—0.8 percent—chance of the asteroid hitting our moon. Now, the agency says the odds of a lunar impact have risen slightly, to 1 percent.
Current analyses, however, are challenged by the fact that the asteroid is traveling away from Earth in its four-year orbit around the sun. It won’t fly by Earth again until 2028, when astronomers will be able to start gathering precise data with ground-based telescopes once more.
“I expect we will continue to see that probability number bounce around, even increase before finally, we resolve it as being 0,” Binzel says to Forbes. “It might seem confusing or worrying, but it is simply the nature of this particular science.”
The asteroid has an estimated diameter of around 130 to 300 feet. While that’s big enough to destroy a major city, it’s not civilization-ending—meaning that even if the impact probability eventually rises to 100 percent, authorities would have time to plan any necessary evacuations.
“People should absolutely not worry about this yet,” David Rankin, an asteroid hunter who identified images of asteroid 2024 YR4 from Catalina Sky Survey archival data, told Space.com’s Robert Lea earlier this month.
Moving forward, as astronomers operate increasingly powerful telescopes, they are likely to discover other, similar asteroids that might initially appear to pose a threat, as Binzel tells Smithsonian magazine in an email. “An object the size of YR4 passes harmlessly through the Earth-moon neighborhood as frequently as a few times per year,” he says. “For perhaps many of these new discoveries, we will have initial uncertainties about their miss distance from Earth. But just like YR4, with a little time and patient tracking, we will be able to rule out entirely any hazard.”
“Rather than making anyone anxious, by finding these objects that are already out there and by pinning down their orbits, we are becoming more secure in our knowledge that any sizable asteroid is not likely to take us by surprise as an unwelcome guest landing on us.”
Editor’s Note, February 21, 2025: This article has been updated to include a comment from Richard Binzel sent to Smithsonian magazine.
