A spent Falcon 9 rocket stage is set to hit the moon on August 5

The discarded upper stage of a SpaceX Falcon 9 rocket will crash into the moon on August 5, offering scientists a rare chance to study an uncontrolled impact on the lunar surface, according to reports citing US officials on July 30.

The stage, weighing about 3,900 kilograms, is expected to strike the moon at around 2:35 a.m. Eastern Time (0635 GMT) on August 5 at a speed of roughly 2.43 kilometers per second, two studies posted on the preprint server arXiv show. The impact is predicted to occur near the Einstein crater on the moon's western limb, and the resulting flash and plume of ejecta should be detectable by ground-based and space-based telescopes.

The rocket body is debris from a January 15, 2025 mission that carried two commercial lunar landers – Firefly Aerospace's Blue Ghost and ispace's Hakuto-R – toward the moon. After releasing its payloads, the upper stage was left in a high Earth orbit crossing the moon's orbit and has been drifting since. It now follows a trajectory that will bring it into the lunar surface.

A team led by Benjamin Fernando of Los Alamos National Laboratory said the impact could serve to test analytical methods for future lunar seismic missions, study the dust and ejecta produced by the collision and assess the risks of artificial space debris strikes. Measurements of the ejected material could also help scientists understand the geology of the impact region and provide data on the moon's composition, the researchers added.