A telescope in Chile has captured footage of Asteroid 2024 YR4, an asteroid large enough to wipe out an entire city. While the city-killer asteroid is currently speeding away from Earth, scientists warn that it might return with a bang in 2032.
NASA’s Asteroid Terrestrial-impact Last Alert System (ATLAS) spotted the asteroid on Dec. 27, 2024, just after YR4 had made a close approach to Earth on Dec. 25. The footage shows the asteroid zooming through the expanse of space as it barrels along its orbit.
At an estimated 130 to 300 feet (40 to 90 meters) wide, Asteroid YR4 is big enough to be considered a city-killer, meaning it could cause catastrophic destruction if it ever collides with Earth. And while the odds of impact remain low, NASA scientists have recently doubled those odds from 1.2 percent to 2.3 percent—or a 1 in 43 chance.
Should YR4 make an unwanted return in December 2032, the consequences would be devastating. Scientists estimate the asteroid would unleash an explosion of 8 megatons, roughly 500 times more powerful than the atomic bomb set off in Hiroshima during World War 2.
Additionally, the possible impact zone, known as the “risk corridor,” stretches over a large area that includes the eastern Pacific Ocean, northern South America, the Atlantic Ocean, Africa, and South Asia.
Because of this large risk corridor, this city-killer asteroid isn’t just a threat to one region—it could spell disaster wherever it lands. However, it’s important to note that NASA isn’t panicking— at least not yet. More observations in March and April will help astronomers refine YR4’s trajectory, potentially reducing the impact risk to zero.
Another close approach in 2028 will also provide more data, which could further refine the asteroid’s trajectory in 2032. NASA always plans to use the James Webb Space Telescope to look more closely at YR4 to determine its exact size and composition. After April, keeping track of the asteroid from the ground will become impossible as it gets too far away from us.
If the impact probability for the city-killer asteroid remains above one percent, scientists may consider deflecting the asteroid—a tactic recently tested with NASA’s DART mission, which successfully altered an asteroid’s course in 2022. For now, though, there’s still a 97.7 percent chance it will miss Earth.
