The Potential Danger to Satellites due to Ejecta from a 2032 Lunar Impact by Asteroid 2024 YR₄

On 2032 December 22, the 60 m diameter asteroid 2024 YR₄ has a 4% chance of impacting the Moon. Such an impact would release 6.5 MT TNT equivalent energy and produce a ∼1 km diameter crater. We estimate that up to 10⁸ kg of lunar material could be liberated in such an impact by exceeding lunar escape speed. The current overall probability is about 1% that the asteroid will impact the Moon at a location such that more than 10% of the ejected material would accrete to the Earth on timescales of a few days. If this were to occur, the lunar-ejecta-associated particle fluence at 0.1-10 mm sizes could produce up to several years of equivalent background meteoroid impact exposure to satellites in near-Earth space late in 2032. Our results demonstrate that planetary defense considerations should be more broadly extended to cislunar space and not confined solely to near-Earth space.