A four-tonne piece of a SpaceX rocket is expected to crash into the Moon at 5,400mph on Wednesday, creating a new crater and potentially sending a plume of debris up to 62 miles above the lunar surface.
The school-bus-sized object is the spent upper stage of a Falcon 9 rocket launched in January 2025. It is predicted to strike near Einstein crater on the Moon's western edge at around 6.35am GMT on 5 August.
Nothing can now prevent the collision because the abandoned stage has no fuel, working propulsion system or means of receiving steering commands. The impact poses no danger to Earth, but NASA will attempt to observe it as scientists investigate what the collision could reveal about lunar dust and the growing problem of space junk.
Why Nobody Can Stop It
The Falcon 9 launched from Florida on 15 January 2025, carrying Firefly Aerospace's Blue Ghost lander and Japanese company ispace's Resilience spacecraft towards the Moon.
After completing its role, the upper stage released its remaining fuel and was left drifting through space. Unlike Falcon 9 boosters that return to Earth for recovery, this section was travelling too far away to be brought back safely.
A combination of solar activity and gravitational forces later pushed it onto an unavoidable collision course with the Moon. The stage cannot restart its engine or change direction, while launching a separate mission to intercept it would require considerable time and expense.
Although it is frequently described as a 'SpaceX rocket', the object is no longer an active spacecraft under the company's control.
What Happens at 5,400mph?
The Moon has almost no atmosphere, so the rocket stage will not burn up or slow down as it approaches. It is expected to strike the surface at approximately 1.5 miles per second.
NASA estimates that the impact could excavate a crater around 60 feet wide and up to 12 feet deep. The collision will throw lunar soil and rock into the air, forming an ejecta plume that some scientific models suggest could reach between 47 and 62 miles high.
The booster itself is expected to be destroyed instantly.
Researchers believe the plume could remain brighter than the surrounding sky for several minutes. However, the impact site's position near the Moon's western limb will make it challenging to observe from Earth.
The event will not be visible to the naked eye. Astronomers with sufficiently powerful telescopes may have a chance of detecting the initial flash or the illuminated dust that follows, although weather, timing and the Moon's position could affect visibility.
NASA Prepares To Watch the Crash
NASA plans to use available ground and space-based instruments to gather data from the collision. Its Lunar Reconnaissance Orbiter is also expected to photograph the region before and after the impact, helping scientists locate and measure the new crater.
Because researchers know the object's approximate mass, speed and trajectory, they can compare the actual aftermath with computer simulations. That could improve predictions about how artificial objects behave when they strike the lunar surface.
A hollow rocket stage may produce a different plume from a dense asteroid or meteoroid. Understanding that difference could help protect future astronauts, scientific equipment and infrastructure as activity on the Moon increases.
A Warning From Lunar Space Junk
Artificial objects have struck the Moon before. NASA intentionally crashed its LCROSS rocket stage into the surface in 2009 to search for evidence of water, while a discarded Chinese rocket body made an uncontrolled impact in 2022.
The Falcon 9 collision is not expected to cause significant damage to the Moon. Natural objects have produced far larger impacts throughout its history.
However, the crash raises questions about how companies and space agencies dispose of hardware sent beyond Earth. NASA and SpaceX are already discussing ways to reduce the risk of similar uncontrolled lunar impacts as more missions head towards the Moon.
