A spent SpaceX upper stage that once launched two lunar landers is due to strike the Moon in the early hours of Wednesday, producing a crater and a plume of dust and rock that scientists and skywatchers are preparing to observe.
Impact details and observation prospects
Orbit analysts estimate the collision will occur at about 8,700 km/h (5,400 mph) near the Moon’s sunlit western limb, at the edge of the lunar near side. The impactor is expected to hit with the kinetic energy roughly equivalent to three tonnes of TNT, producing a crater that experts calculate could be about 27 metres across and 5 metres deep (roughly 90 ft by 16 ft).
Although the brief impact flash is likely to be faint and last less than a second — making it difficult to detect directly from Earth — the stream of material thrown up by the strike could be visible for tens of minutes. Observers across eastern North America and much of South America may have the best viewing geometry during the event.
- Predicted impact speed: 8,700 km/h (5,400 mph)
- Estimated energy: equivalent to 3 tonnes of TNT
- Predicted crater: ~27 m wide, ~5 m deep (90 ft × 16 ft)
Scientists hope telescopes — professional and amateur — will capture the ejecta curtain rather than the instantaneous flash. The Moon’s low gravity and lack of atmosphere make ejected dust settle slowly and permit longer windows for detection than would be possible on Earth.
Scientific value and cautionary note on debris
Researchers are interested in the event for two reasons: it offers a rare, natural experiment in impact physics at the Moon, and it helps assess the hazard posed by orbital debris to future lunar operations. Benjamin Fernando of Los Alamos National Laboratory, encouraging community observations, notes the value of such data for understanding risks to astronauts and equipment on the lunar surface.
“Things are getting crowded up there,” said Bill Gray, a veteran space‑tracking analyst planning to view the aftermath from New Brunswick, Canada.
Experts emphasise that this particular object poses no danger to people on Earth or to critical assets, but the incident underlines a broader trend: as more launches place mass into cislunar and Earth orbit, the potential for accidental encounters grows. Space specialists have also pointed out that the impact might have been avoided had the rocket stage been given a deliberate burn to escape the Moon’s vicinity and enter a heliocentric orbit following its mission.
Context and follow‑up
This will be at least the second confirmed case of a spent rocket body unintentionally striking the Moon; a Chinese rocket tank was known to have created craters on the lunar far side in 2022. On this occasion, the collision will occur on the near side, where subsequent imaging from lunar orbiters could resolve the new crater.
| Parameter | Estimate |
|---|---|
| Impact speed | 8,700 km/h (5,400 mph) |
| Energy | ~3 tonnes TNT equivalent |
| Predicted crater size | ~27 m × 5 m (width × depth) |
Spaceborne observers, including lunar orbiters such as NASA’s Lunar Reconnaissance Orbiter and other international craft, are expected to attempt follow‑up imaging to locate and characterise the impact site. Such observations can validate ground‑based detections and help calibrate models of how artificial objects behave on collision with the lunar surface.
For now, the event offers a reminder that missions which leave large objects uncontrolled in Earth–Moon space carry consequences beyond their nominal tasking. As lunar exploration and commercial activity increase, experts say more stringent end‑of‑mission disposal practices will be needed to limit risks to science, exploration and heritage on and around the Moon.
