A spent Falcon 9 rocket upper stage is expected to crash into the Moon on 5 August at around 2:35am ET, near the Einstein Crater, in an event astronomers on Earth should be able to observe with ground-based telescopes. The impact was first predicted by Bill Gray, creator of the Project Pluto planetarium software, who modelled the stage's drifting orbit to forecast its eventual path into the lunar surface. It matters because the collision offers scientists a rare chance to study an artificial impact on the Moon in real time, helping researchers understand dust and plume behaviour and the wider hazards posed by space debris.

The rocket stage originally launched on 15 January 2025, carrying Firefly Aerospace's Blue Ghost lunar lander and Japan's ispace Hakuto-R lander before running out of fuel and being left stranded in space. It measures roughly 39 feet long and 13 feet wide, weighs about 4,000 kilograms, and will strike the lunar surface at approximately 5,400mph. Despite its size relative to typical natural impactors, researchers say its effect will be modest since it is a hollow shell travelling relatively slowly; visibility will be best from South America and low-to-mid latitude parts of North America, away from the West Coast, where the Moon will be higher and the sky darker at the time of impact.