A discarded SpaceX rocket stage will hit the Moon on August 5 at 5,400 mph

A discarded SpaceX Falcon 9 upper stage is on course to crash into the Moon on August 5 at approximately 2:34 AM ET, striking the lunar surface near Einstein crater at roughly 5,400 miles per hour. The stage has been drifting in an unstable, chaotic orbit for the past eighteen months after launching Firefly Aerospace's Blue Ghost Mission 2 toward the Moon in January 2025 — stranded with too little fuel to deorbit safely and too little velocity to escape Earth's gravity entirely.

How a rocket stage ends up crashing into the Moon by accident

After deploying its payload, the spent upper stage was left in a 26-day elliptical orbit with no way to control its trajectory. Over the following eighteen months, the combined gravitational pull of Earth, the Moon, and the Sun — along with the subtle but cumulative push of solar radiation pressure — gradually walked the stage onto a collision course with the lunar surface. This is not a planned mission; it's an unintentional consequence of orbital mechanics acting on space debris that had no propulsion left to avoid it.

What scientists expect to see

At impact velocity, the rocket stage will almost certainly vaporize on contact, producing a brief flash and excavating a crater estimated at roughly 65 to 100 feet across and about 16 feet deep. The resulting cloud of ejected dust and debris may remain observable for several minutes as it settles back to the surface. A coordinated observation campaign spanning three continents — backed by a preprint from 23 researchers — argues the ejecta plume rising above the lunar limb could provide the clearest view anyone has captured of a human-made object striking another world, assuming visibility conditions cooperate; the Moon will be just over half-illuminated at impact time, with the strike zone near the bright edge of the disk, which could wash out fainter details of the flash.

Both NASA's Lunar Reconnaissance Orbiter and South Korea's Danuri spacecraft are positioned to photograph the impact site before and after the collision, giving researchers before/after imagery to measure the actual crater dimensions against pre-impact predictions.

Why this matters beyond a curiosity

The observation campaign is explicitly testing a pipeline for localizing lunar impacts using flash timing combined with orbital mechanics modeling — a capability directly relevant to the seismometer networks planned for NASA's Artemis program. As lunar surface infrastructure expands under Artemis, the ability to detect, locate, and characterize meteoroid and debris impacts in real time becomes an operational safety requirement, not just a research interest. A known-mass, known-velocity impact like this one gives researchers a rare calibration point — they know almost exactly what hit the Moon and how fast, which lets them validate their detection and localization methods against ground truth in a way that's normally impossible with natural meteoroid impacts of unknown mass.

The event also underscores a growing practical problem: as more missions leave hardware in cislunar space, uncontrolled impacts like this one are likely to become more frequent, making the tracking and eventual deorbiting of spent stages an increasingly important part of mission planning for any company or agency launching toward the Moon.

As reported by Space.com, with additional detail from CNBC.