Astronomers have had their eyes locked on Asteroid 2024 YR4, a space rock hurtling through the cosmos with a trajectory that initially suggested a slim—but concerning—chance of impacting Earth. Headlines called it a “city-killer” due to its potential to cause catastrophic destruction. But now, the latest update for the city-killer asteroid has delivered an audible sigh of relief as its chances of hitting Earth in 2032 have dropped to virtually zero.
When Asteroid 2024 YR4 was first discovered, its impact probability steadily climbed to 3.1% by February, triggering a heightened planetary defense response. While this may not seem like much, it was one of the highest-risk asteroids on record, prompting astronomers to scramble to gather more precise data before it faded into the sun.
At approximately 40 to 90 meters (130-300 feet) wide, the asteroid is far smaller than the 10-kilometer (6-mile) asteroid that wiped out the dinosaurs but still large enough to devastate a major city. Experts estimated that if it hit Earth, it could unleash an explosion equivalent to 7.8 megatonnes of TNT, far surpassing the most powerful nuclear detonations ever conducted. Thankfully, the latest updates for the city-killer asteroid bring some much-needed hope.
Thanks to extensive observations from NASA and other space agencies, scientists have refined 2024 YR4’s trajectory. This has, thankfully, lowered the chances of the city-killer asteroid’s impact probability from more than a 3 percent chance to just 0.0017 percent—a statistical non-threat.
Astronomers now say with 99.9983 percent certainty that the asteroid will safely pass by Earth without incident. In fact, it now ranks zero on the Torino Scale, which assesses asteroid impact hazards. This means it poses no threat at all, much to the relief of planetary defense experts.
While 2024 YR4 is no longer a concern, astronomers warn that these types of alerts will become more frequent as telescopes improve. The Vera Rubin Observatory is expected to detect thousands of new asteroids, some of which may temporarily appear as threats just like the city-killer asteroid before this latest update, at least until additional observations refine their paths.
But these alerts aren’t cause for panic, experts explain. Instead, it’s a sign of progress. Progress that we—hopefully—won’t be caught unexpectedly by an asteroid capable of killing thousands hurtling towards Earth. So long as we can detect them, we can estimate their paths and prepare defenses, like NASA’s D.A.R.T. spacecraft, which successfully changed the path of an asteroid in 2022.
