Key facts
- An empty SpaceX Falcon 9 rocket upper stage crashed into the Moon on Wednesday.
- The impact occurred near the Einstein crater at a speed of about 5,400 mph.
- The collision is expected to provide valuable data for planetary geologists.
- Scientists will use the event to test models of crater formation and debris distribution.
- This is not the first time a human-made object has intentionally or accidentally impacted the Moon.
An empty upper stage of a SpaceX Falcon 9 rocket has crashed into the Moon, creating a new crater near the Einstein landmark and presenting scientists with a unique research opportunity. The collision occurred on Wednesday at approximately 5,400 mph (8,700 km/h).
The rocket's spent stage, weighing at least 4,000kg and roughly the size of a five-storey building, had been drifting in a long orbit for 18 months after launching lunar landers in January of the previous year. Gravitational pulls from Earth, the Moon, and the Sun, along with solar radiation pressure, gradually altered its trajectory, putting it on a collision course with the Moon.
While the impact itself created a brief flash too faint to be seen by most observers, it is expected to have produced a plume of dust stretching up to 100km. Larger observatories in the Americas, where the sky was dark at the time of impact, are analyzing the data. South Korea's Danuri orbiter passed near the site shortly before the event, and its team may release footage after analysis. Nasa's Lunar Reconnaissance Orbiter is scheduled to photograph the impact site in the coming days.
For planetary geologists, this accidental impact is a valuable scientific event. It allows them to test models of how impacts create craters, eject debris, and generate seismic tremors on the lunar surface. Understanding these processes can inform the design of safer lunar landers and future Moon bases. The material ejected from beneath the surface may also offer new insights into the Moon's geology and the formation of the Earth-Moon system billions of years ago.
This is not the first time a human-made object has impacted the Moon. Dozens of spacecraft have crashed since 1959, some deliberately for scientific purposes, such as Nasa's LCROSS mission in 2009 which searched for water ice. The last confirmed accidental impact in 2022 was attributed to a leftover booster from a Chinese lunar mission.