Falcon 9 Upper Stage to Strike Moon on August 5

A spent upper stage of SpaceX’s Falcon 9 launch vehicle, which delivered the Blue Ghost lander for Firefly Aerospace and the Hakuto-R lunar rover for ispace in January 2025, is on a trajectory to collide with the Moon’s surface on August 5. Amateur astronomer Bill Gray calculated that the 10,800-pound (?4.9-tonne) piece will impact near the rim of Einstein crater on the near-side limb, at roughly 06:35 UTC (about 2:34 a.m. EDT). The stage will strike at an estimated 5,400 mph, releasing kinetic energy comparable to three tons of TNT.

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A preprint authored by 23 astronomers—including Gray—urges both professional and amateur observers to record the event. Ground-based telescopes in the Americas will attempt to capture a brief flash and any ejecta plume that may become visible against the dark background beyond the limb. Space-based assets are also slated to monitor the impact: NASA’s Lunar Reconnaissance Orbiter (LRO) will image the site before and after the collision, while South Korea’s Pathfinder Lunar Orbiter will seek to document the impact and its aftermath. The authors note that detecting a flash on the sunlit hemisphere is unprecedented, but the proximity to the lunar limb could aid visibility of ejected material.

Scientific AmericanScientists are preparing to observe an artificial collision of a rocket with the moon

Impact events on the Moon are extremely rare, and a controlled-trajectory collision offers a unique laboratory for studying crater formation, the dynamics of ejected regolith, and the behavior of lunar dust in low-gravity conditions. Data gathered from this event are expected to improve models of debris hazards for upcoming crewed missions and permanent lunar bases, and to refine techniques for tracking artificial objects in lunar orbit.

Scientists are preparing to observe an artificial collision of a rocket with the moon Scientific American

• Object mass: 10,800 lb (?4.9 t)

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• Impact speed: ~5,400 mph (?2.4 km/s)

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• Energy release: ~3 t TNT equivalent

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• Impact time: 06:35 UTC on August 5

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• Location: Near Einstein crater, edge of the near-side limb

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Following the impact, LRO and Pathfinder will acquire high-resolution images of the new crater to compare with pre-impact baselines. The observations are intended to feed into lunar-environment models that will support NASA’s Artemis program and international plans for sustained lunar presence.

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