A discarded SpaceX rocket upper stage is on course to collide with the moon on Wednesday, becoming only the second known unintentional human-made impact on the lunar surface. The 4,500-kilogram booster segment will strike near the Einstein crater on the moon's sunlit western side at roughly 8,700 kilometres per hour, releasing energy equivalent to three tonnes of TNT.
The impact is expected to carve a crater nearly 27 metres wide and five metres deep, ejecting debris visible through telescopes for tens of minutes. NASA's Lunar Reconnaissance Orbiter and South Korea's Danuri satellite will photograph the site before and after the strike.
The rocket launched in January 2025 carrying two lunar landers — Firefly Aerospace's Blue Ghost, which achieved the first fully successful private moon landing, and a Japanese ispace lander that crashed. The collision could have been avoided had the stage been directed toward a solar orbit. A Chinese rocket fragment created two craters on the lunar far side in 2022. Astrophysicist Jonathan McDowell warned such debris impacts could become problematic as long-duration lunar bases become reality.