2024 YR4 has entered unusual territory. ESA’s latest calculation places its chance of striking Earth on December 22, 2032, at 2.8%—slightly above the 2.7% once calculated for Apophis, the asteroid that dominated headlines two decades ago.
That comparison makes YR4 historically interesting, not inevitable. Roughly 97 out of 100 modeled paths still miss Earth, and the estimate will continue moving as telescopes add measurements. Apophis itself is a useful precedent: better tracking eventually removed its impact scenario, while leaving behind one of the most anticipated close flybys in astronomy.
YR4 is giving today’s planetary-defense network its own live workout. Each tiny point of light helps trim a future cloud of possible positions. Right now, Earth occupies a small but meaningful part of that cloud, so the world’s observatories are treating every clear night as valuable. This is why asteroid surveys exist: find the difficult object early, share the measurements quickly, and follow the evidence wherever it goes.