SpaceX rocket stage to hit Moon next week; outcome uncertain

An upper stage of a SpaceX Falcon 9 rocket is on a collision course with the Moon, with impact expected on August 5, 2026. The rocket stage was part of the January 15, 2025, launch that sent Firefly Aerospace's Blue Ghost-1 lunar lander and Japan's ispace Resilience lander toward the Moon.

International scientists, publishing their findings on the arXiv server, predict the impact will occur near the Einstein and Bell craters on the Moon's western edge. They anticipate the collision could generate a significant plume of debris, a so-called ejecta cloud, potentially reaching 75 to 100 kilometers above the lunar surface.

William Jo from the University of Texas at Austin, a co-author of the study, stated that the cloud could be several times brighter than the dark sky background for the first few minutes after impact. This brightness might make it visible to Earth-bound observers using sufficiently sensitive telescopes. However, scientists caution that these predictions are based on a nominal scenario, and the actual event could differ.

The most crucial aspect of this event, according to experts, lies in what happens after the initial flash. Observing the impact provides a unique chance to study how material behaves when ejected from the lunar surface and to compare real-world events with existing computer models. Research led by Benjamin Fernando of Los Alamos National Laboratory also suggests the ejecta cloud could be captured from Earth and space.

Scientists aim to use this impact to develop more precise methods for identifying impact sites on the Moon. The data gathered could be invaluable for studying seismic consequences, lunar dust dynamics, debris clouds, and assessing potential risks for future astronauts and infrastructure. Some ejected particles might travel nearly 1000 kilometers from the impact site, a factor of importance for future missions as space debris from artificial impacts could pose a risk across large areas of the Moon. NASA's Lunar Reconnaissance Orbiter (LRO) is expected to provide additional data by flying over the predicted impact zone before and after the event, enabling comparisons of the lunar surface.

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The cloud could be several times brighter than the dark sky background for the first few minutes after impact, making it potentially visible to observers on Earth with sufficiently sensitive telescopes.