A spent SpaceX Falcon 9 upper stage is expected to crash into the moon on Wednesday, potentially creating a debris plume visible from Earth.

A spent SpaceX Falcon 9 upper stage is scheduled to impact the moon's sunlit western limb near the Einstein crater on Wednesday at approximately 6:34 am UTC. Traveling at over 5,400 mph, the rocket stage is expected to create a debris plume that may be visible from Earth using a telescope. This event marks a rare opportunity to observe an impact on the moon's sunlit face, which has never been recorded before.

Predicting the Lunar Impact

Researchers from the University of Texas at Austin have modeled the potential impact using high-resolution physics simulations. The study, led by doctoral candidate William Jo, suggests the 3,900-kilogram hollow metal structure will collapse inward upon impact, displacing approximately 12,700 kilograms of lunar debris. The simulation predicts a broad curtain of soil and a faster vertical spike of material. However, scientists note that the model assumes a direct, engine-first impact. A more likely glancing strike could result in a smaller, dimmer plume. Astronomer Laurence Trafton suggests that while the plume could be visible, its brightness may be 30 to 300 times fainter than the moon itself, making observation challenging due to scattered moonlight and atmospheric conditions.

Scientific and Operational Significance

Monitoring the collision offers researchers a chance to study lunar surface composition and the behavior of debris, which is critical as space agencies plan for future lunar missions and potential bases. Scientists are particularly interested in how such impacts displace abrasive lunar dust, which poses a significant challenge for future astronauts and equipment. This event follows previous, often unplanned, lunar impacts by space hardware. While past missions, such as NASA's 2009 impact, have successfully detected water ice in debris plumes, this specific collision provides data on the potential risks posed by spent hardware left in orbit during an increasingly active era of lunar exploration.