A four-ton piece of a SpaceX Falcon 9 rocket that has been adrift in space since January 2025 is hours away from crashing into the moon, an unintentional collision that will carve a new crater into the lunar surface at roughly 5,400 miles per hour.
The object, described as about the size of a school bus, is the spent upper stage of a Falcon 9 that carried Firefly Aerospace's lunar lander toward the moon last year. After helping set the lander on its course, the discarded stage was left in orbit, and its trajectory has now put it on a direct collision path with the moon. The impact poses no danger to Earth, but it will permanently alter a small patch of the lunar landscape.
Because the crash was not planned, it gives researchers a rare chance to study a lunar impact under unusually well-documented conditions. Unlike an asteroid or meteoroid, whose size and speed are often uncertain, this impactor is a known piece of hardware with a recorded history and a confirmed mass. Observations of the collision and the crater it leaves behind could improve scientific understanding of how high-speed impacts shape the surfaces of airless bodies across the solar system.
NASA has announced it will attempt to observe the rocket part's impact with the moon. The agency hopes to capture data or imagery from the event, which could offer insights into the structure of the lunar surface. Fresh craters formed under known impact conditions are extremely rare, which makes the accident scientifically valuable despite its unintended origins. Data gathered from the observation could also inform planning for future lunar missions.
The Falcon 9's second stage did its job in January 2025, when it helped send Firefly Aerospace's lunar lander on its way to the moon. SpaceX's Falcon 9 is a partially reusable vehicle: the first stage returns to Earth and lands for reuse, but the second stage, which fires in orbit, is not recovered. On deep-space missions, upper stages are typically left in orbits considered safe or allowed to drift away from Earth. In this case, the stage's orbit slowly evolved over the following months until a collision with the moon became the outcome.
The approaching impact also underscores a growing concern for the space industry: debris is no longer just an Earth-orbit problem. With more missions traveling to the moon and beyond, the amount of discarded hardware in deep space is increasing, and such objects are far harder to track than satellites in low Earth orbit. Monitoring networks that watch Earth orbit are not designed to follow interplanetary debris, so abandoned rocket parts can travel for years before their paths cross another celestial body.
While the collision will be dramatic, its practical consequences are limited. The main result will be a new, measurable crater on the moon, along with scientific observations that can help refine models of lunar impact processes. The moon has no atmosphere to erode or bury such a mark, so the crater will remain visible for a very long time, serving as a lasting record of the event and a continuing subject of study.
The stage is being tracked as it closes in for its final hours. Once it strikes, the impact itself will be brief, but the crater it leaves behind, a permanent mark of human activity in space, will remain on the lunar surface for years.
