YR4’s story began with a faint dot found by ATLAS in Chile just after Christmas 2024. Early orbit calculations left a small possibility that the asteroid could meet Earth on December 22, 2032. As the odds crossed 1%, international notification systems kicked in and observatories hurried to gather more data.
For a short time, the estimated Earth-impact probability climbed as high as a few percent. That was not a mistake or an overreaction: it was the best assessment supported by the available observations, and it crossed the threshold for international attention.
The response became a worldwide relay race. Survey telescopes supplied positions, orbit specialists recalculated the 2032 encounter, and Webb later measured a target so faint that few instruments could still see it. YR4’s close Earth–Moon passage turned an anonymous dot into a live demonstration of how humanity maps something small, dark, and millions of miles away.