Using data from NASA's James Webb Space Telescope observations collected on February 18 and 26, experts from NASA's Center for Near-Earth Object Studies at the agency's Jet Propulsion Laboratory in Southern California have refined near-Earth asteroid 2024 YR4's orbit and are ruling out a chance of lunar impact on December 22, 2032.With the new data, 2024 YR4 is expected to pass by the lunar surface at a distance of 13,200 miles (21,200 km).
The outcome vindicates a rigorous, evidence-based approach to planetary risk assessment.Previous analyses, made before the incorporation of these new observations, suggested 2024 YR4 had a 4.3% chance of lunar impact on this date. When the asteroid was first discovered in late 2024 by the NASA-funded Asteroid Terrestrial-impact Last Alert System station in Chile, early calculations gave it a brief moment as perhaps the most hazardous object known. Rather than downplaying uncertainty, scientists amplified their observational efforts.
The technical feat itself is remarkable.Since spring of 2025, the asteroid has been unobservable from both Earth and space-based observatories except for this use of Webb to make among the faintest ever observations of an asteroid.An international team coordinated through ESA's Near-Earth Object Coordination Centre and NASA's CNEOS, led by the Johns Hopkins Applied Physics Laboratory, identified two narrow windows in February 2026 when the geometry might allow Webb to catch YR4 against a sparse star field. The position of those background stars was known with extraordinary precision thanks to ESA's Gaia mission, itself a decade-long project to map the sky in three dimensions.
Here lies a genuine strength of collaborative international science. Rather than one nation racing alone, NASA, the European Space Agency, and the Johns Hopkins Applied Physics Laboratory coordinated urgent observing time. This division of effort with shared standards has become how modern planetary defence works. The system identified two narrow observation windows and seized them both.
Yet this success also illustrates a deeper principle worth considering: how initial uncertainty naturally tends to provoke alarm before clarification arrives. When 2024 YR4's impact probability was revised upward from initial estimates, public concern was justified. The early 1-in-100 chance of an Earth impact warranted international attention. As more data arrived, that picture shifted. This is not a failure of science but its intended mechanism. Incomplete data generates wider ranges of possible outcomes. Better data narrows those ranges.
Over time with more observations collected by observatories around the world, NASA concluded the object poses no significant impact risk to Earth on December 22, 2032, or through the next century. The global planetary defence framework consists of multiple observatories, data-sharing protocols, and coordinated teams working to detect and track near-Earth objects before they pose a genuine threat.In 2016, NASA established the Planetary Defense Coordination Office (PDCO) to manage the agency's ongoing mission of finding, tracking, and better understanding asteroids and comets that could pose an impact hazard to Earth.
What 2024 YR4 demonstrates, ultimately, is that institutional investment in space surveillance and international cooperation yields measurable returns. The Moon is safe. Earth is safe. And the system designed to protect both has demonstrated that it can absorb new information, refine its assessments, and communicate with confidence when the data supports it. The real question for policymakers is not whether to fund such efforts, but how to ensure they continue to improve as new threats inevitably emerge.