In March 2026, NASA used data from the James Webb Space Telescope to rule out a 2032 lunar impact chance for which asteroid?

In early March 2026, NASA announced that the asteroid 2024 YR4 would not impact the Moon in 2032, definitively ruling out a potential collision that had previously held a 4.3% chance. This crucial update came thanks to new observations made by the powerful James Webb Space Telescope (Deals) (JWST) in February 2026. The asteroid, discovered in late 2024, had initially sparked concerns due to its close approach trajectory, with early analyses even suggesting a slight risk of Earth impact before that possibility was ruled out.

The James Webb Space Telescope’s highly sensitive infrared instruments were instrumental in refining the asteroid's orbital path. Prior to these observations, 2024 YR4 was too faint to be accurately tracked by other telescopes, having been unobservable from both Earth and other space-based observatories since spring 2025. The JWST's unique capabilities allowed astronomers to gather precise data on the asteroid's position, significantly improving the accuracy of future trajectory predictions.

With the refined data, experts from NASA's Center for Near-Earth Object Studies confirmed that on December 22, 2032, asteroid 2024 YR4 is expected to pass safely by the lunar surface at a distance of approximately 13,200 miles (21,200 kilometers). This close but safe encounter is still closer than some artificial satellites orbit Earth, highlighting the importance of continuous monitoring of near-Earth objects. The asteroid, estimated to be about 174 to 220 feet (53 to 67 meters) in diameter, has been dubbed a "city-killer" due to its potential destructive force if it were to strike a populated area.