Humanity has spent several thousand years admiring the Moon, writing poems about it and blaming it for suspicious behaviour by wolves. On August 5, 2026, at approximately 06:35 UTC, we intend to add another chapter to this distinguished relationship by hitting it with a used rocket stage.
The object in question is the upper stage of a SpaceX Falcon 9. In early 2025 it helped send Firefly Aerospace’s Blue Ghost and ispace’s Hakuto-R Resilience landers towards the Moon. Its useful career concluded, the stage was left in a highly elliptical, Moon-crossing orbit around Earth. Orbital mechanics—which is essentially celestial bookkeeping with severe consequences—has now scheduled its final appointment.
According to a recently published observational planning paper, the stage should strike near Einstein Crater, close to the Moon’s eastern limb as seen from Earth. The impact velocity will be about 2.43 kilometres per second. That is slow by meteorite standards, but still considerably faster than recommended for parking.
The rocket stage is roughly twelve metres long, four metres wide and probably weighs around 4,000 kilograms. Its impact energy is estimated at 11.8 gigajoules, roughly equivalent to three tonnes of TNT. The researchers expect it to excavate more than a million kilograms of lunar soil—between 150 and 200 times the mass of the rocket itself.
This is an impressive return on investment for a vehicle that no longer has an engine switched on.
The resulting crater should be somewhere between twenty and thirty metres across, with one estimate placing it at twenty-seven metres wide and five metres deep. It may even be a double crater. Rocket stages are large, thin-skinned and partly hollow, and the Falcon 9 stage might break apart immediately before impact. Scientists refer to one possible process as “decapitation,” which suggests that even spacecraft can have a surprisingly theatrical final act.
Before the crater comes the flash. Unfortunately, nobody knows how bright it will be. The impact site will be on the illuminated part of the Moon, where detecting a brief burst of light is rather like trying to notice someone striking a match in front of a cinema screen.
Natural meteoroids usually hit the Moon at tens of kilometres per second and produce powerful shock waves. This rocket is arriving at a comparatively leisurely pace. Its flash will depend heavily on whether it hits loose regolith or exposed bedrock, as well as on which end—or side—of the tumbling stage reaches the ground first. Predictions range from detectable to “thank you for spending the night staring at nothing.”
That uncertainty is precisely what makes the event scientifically interesting. Although astronomers have recorded hundreds of natural lunar impact flashes, no reliable brightness measurement has ever been published for an artificial impact. The Falcon 9 therefore offers a rare chance to compare models with an impactor whose size, mass and speed are approximately known.
The flash will probably last less than a second, so observers are advised to record at twenty frames per second or more. A photograph taken at exactly the wrong moment will otherwise provide an exceptionally detailed record of the Moon doing nothing unusual.
Professional observatories are preparing high-speed cameras and spectrographs. Researchers hope to search the flash and plume for elements including sodium, potassium, hydroxyl and perhaps lithium. Falcon 9 stages have previously produced lithium emissions while re-entering Earth’s atmosphere, and lithium has a useful spectral line at 670.8 nanometres. In other words, the rocket may briefly colour-code its own destruction.
Amateur astronomers are explicitly invited to participate. Even modest telescopes may contribute useful observations, although the Americas have the best geography: at 06:35 UTC, much of North and South America will be in darkness with the Moon above the horizon. European observers face a more heroic challenge. In Germany the event occurs at about 08:35 summer time, when the Sun has already begun its daily campaign against astronomy. Infrared observations may nevertheless have a chance.
The flash is only the opening number. Simulations suggest that the collision will throw a plume of lunar material several kilometres above the surface. Large particles will fall back within seconds, while finer dust may remain aloft for minutes. Some ejecta could travel hundreds of kilometres across the Moon before landing, a reminder that on a world without air, throwing a stone can become a regional planning issue.
NASA’s Lunar Reconnaissance Orbiter is expected to take before-and-after images of the site. Korea’s Pathfinder Lunar Orbiter will make an especially close pass: the rocket stage should come within a few kilometres of it roughly two minutes before impact. This is perfectly safe by the standards of interplanetary navigation and deeply alarming by the standards of motorway driving.
Artificial lunar impacts are not new. Luna 2 became the first human-made object to strike the Moon in 1959. Apollo rocket stages were deliberately crashed to generate signals for lunar seismometers, and NASA’s LCROSS mission excavated water-bearing material near the south pole in 2009. What is changing is the traffic. More spacecraft are entering cislunar space, and more discarded hardware will eventually need somewhere to go.
The August impact is therefore both a scientific opportunity and a modest warning from the future. We are beginning to export one of Earth’s most successful products—unwanted machinery—to the Moon.
For now, however, the event deserves to be watched. It has everything: uncertain predictions, enormous telescopes, citizen scientists, orbital suspense and a four-tonne protagonist with no steering. If the flash is visible, we will learn something about lunar impacts. If it is not, scientists will still obtain valuable constraints.
And the Moon, maintaining its customary professionalism, will absorb the complaint without atmosphere.
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