2024 YR4 is a newly spotted asteroid with the potential to hit Earth—and its chances of smashing into our planet in 2032 is definitely more than zero.
I realize that “definitely more than zero” will cause some disquiet in the comments, so to be specific: There is a 1.2% chance the asteroid hits Earth based on very preliminary calculations. Which means—obviously—a 98.8% chance the rocky object misses us! But those odds are still upsettingly high, so let’s bear down on what we know about the recently discovered asteroid.
The Asteroid Terrestrial-impact Last Alert System (ATLAS) first spotted 2024 YR4 on December 27, 2024. At that point the asteroid was 515,116 miles (829,000 kilometers) from Earth. The asteroid is currently moving away from our planet but its next close approach will occur in December 2028.
As noted, the current 1-in-83 odds of an asteroid impact are preliminary; astronomers will refine these estimates over time as they gather more data. According to NASA Jet Propulsion Laboratory’s Center for Near Earth Object Studies, calculated impact probabilities “can easily be inaccurate by a factor of a few, and occasionally by a factor of ten or more.” So with that caveat, let’s dive into 2024 YR4 and what sort of danger it may pose to our pale blue dot.
CNEOS reports that the asteroid is 180 feet (55 meters) across, and its speed at (potential) impact estimated at 10.76 miles per second (17.32 kilometers/second). The center reports six distinct possible impact events between 2032 and 2074, with the highest likelihood of impact being in 2032—December 22 of that year to be exact. Feel free to mark your calendars. It’s important to point out that the probability decreases with each subsequent pass the asteroid makes, with the 2032 date the only one qualifying as a Torino 3 level risk.
On the Torino Impact Hazard Scale—a way of measuring the danger posed by asteroids—2024 YR4 merits attention by astronomers, as the encounter is less than a decade away, but collision with Earth is hardly a sure thing. The object’s level-three rating also means that, “Current calculations give a 1% or greater chance of collision capable of localized destruction,” CNEOS’ website states. However, “Most likely, new telescopic observations will lead to re-assignment to Level 0,” or a “No hazard” rating. We’re certainly hoping this will be the case.
As we’ve previously discussed, potentially hazardous asteroid (or PHAs) are routine interlopers in our part of the solar system. Despite their names, the asteroids rarely pose a threat to Earth, but are objects large enough to survive entry into Earth’s atmosphere.
Though the asteroid is not large enough to pose a global threat, it would still release a tremendous amount of energy if it were to make impact on Earth. According to NASA, a strike from the asteroid would release about 8 megatons of energy—more than 500 times the energy released by the atomic bomb dropped on Hiroshima in 1945, and comparable to the energy released in the Tunguska blast of 1908.
As EarthSky points out, the only other asteroid to score higher on the Torino scale is 99942 Apophis, which for a short time in 2004 was listed on the Torino scale as a level 4. The threat posed by Apophis has since been downgraded to a zero on the scale, as astronomers ruled out any significant impact risk for the next 100 years.
The asteroid’s characteristics—its speed, magnitude, heck, even its mass—are subject to change as scientists continue to monitor its path through space. The situation could turn out to be less of a threat, but also could become more alarming as the asteroid whips back around towards our planet.
One thing is certain: It’s critical that scientists keep an eye on the dynamic skies, filled with objects that could pose as existential a threat to humankind as another asteroid did the dinosaurs some 66 million years ago. That’s why NASA demonstrated the ability to redirect an asteroid back in 2024—it’s hopefully a skill scientists never have to utilize, but one that’s reassuring to have.
