2024 YR4 first caught astronomers’ eyes on December 27, 2024, and was marked as an asteroid that may hit Earth in eight years’ time. Now, the asteroid’s impact odds have reached their highest likelihood yet.
The asteroid has a 1-in-32 chance of hitting Earth in 2032, according to the latest (and constantly updated) odds from NASA’s Center for Near-Earth Object Studies Sentry tool. That translates to a 3.1% chance of Earth impact—which of course also means a 96.9% chance that the rock misses our planet altogether.
That number means both a lot and very little at the same time. It means a lot because the asteroid tops CNEOS’ impact probability chart, meaning the rock’s cumulative likelihood of impact with Earth is the greatest compared to other closely watched asteroids.
NASA is constantly remodeling the asteroid’s impact likelihood—as well as that of many other Potentially Hazardous Asteroids, or PHAs, flying through space. On January 28, 2024 YR’s impact odds were 1-in-83, or 1.2%. That number charted up and, by early February, the rock had a 1-in-63 (1.58%) chance of hitting our world. On February 10, the odds jumped yet again, this time to a 1-in-45 chance, or a 2.2% chance of striking Earth. In response, NASA has scheduled some observation time with the Webb Space Telescope to further study the suddenly concerning asteroid.
It’s important to remember that, based on prior precedent, the odds of an asteroid impact often rise before they fall. We hope that’s what’s happening here. As Bruce Betts, The Planetary Society’s chief scientist, explained to Gizmodo, more observations and modeling of the asteroid decrease uncertainty in its projected path. If Earth remains in that corridor of uncertainty, the odds of an impact rise. Only when the asteroid’s path can be predicted with such precision that Earth falls outside of the range will the odds plummet to zero after incrementally rising.
As it stands, there’s a nonzero chance that 2024 YR4 will hit Earth in seven years. Should that happen, the impact would be devastating on a local scale. The asteroid’s width is anywhere between 131 feet (40 meters) and 295 feet (90 m), so the destruction it could cause is similarly variable. Assuming the lower side of that range, an impacting asteroid would still cause devastation; NASA indicated the impact would produce about 8 megatons of energy, comparable to the Tunguska blast of 1908.
According to the International Asteroid Warning Network, the impact risk corridor for the asteroid “extends across the eastern Pacific Ocean, northern South America, the Atlantic Ocean, Africa, the Arabian Sea, and South Asia.”
2024 YR4 is currently a 3 on the Torino Impact Hazard Scale, meaning it has “1% or greater chance of collision capable of localized destruction,” CNEOS says, though “Most likely, new telescopic observations will lead to re-assignment to Level 0.” Despite the slim odds, it’s better to be prepared than not, and to have Earth’s telescopes continually monitor the object.
The asteroid is currently heading away from Earth and won’t swing by again until 2028 (note: there is no chance of impact in 2028). By April, the asteroid will likely be too faint for even the largest telescopes to observe, so time is of the essence. Astronomers are collecting as much data on the potentially hazardous rock as they can before that moment, knowing that once it’s out of sight, they won’t have a chance to get more information for a few years.
Astronomers need to gather refined estimates of 2024 YR4’s precise orbital elements, velocity, spin, size, shape, rotation, and density, along with other key factors like its composition, surface properties, and how non-gravitational forces—such as the Yarkovsky effect—might alter its trajectory.
Several years ago, NASA’s DART mission proved that scientists could change the trajectory of an asteroid. But there’s no guarantee that such a trick can be repeated—and frankly, no one wants to be in a position where we’re forced to find out. Rest assured, scientists are working to determine the exact path of 2024 YR4. Once that’s established—and we (hopefully) confirm that Earth is almost certainly not at risk—then scientists can discuss next steps.