A spent SpaceX Falcon 9 upper stage is believed to have struck the Moon early Wednesday, although scientists have yet to visually confirm the impact.
The object, officially designated 2025-010D, was predicted to hit the lunar surface near the Einstein and Bell craters at approximately 6.35 am (1035GMT), according to NASA and independent tracking calculations.
NASA's Center for Near Earth Object Studies had determined that the rocket stage had a 100% probability of hitting the Moon.
Astronomer Bill Gray, who tracked the object using publicly available observations, estimated that the approximately 4,900-kilogram (10,800-pound) stage would strike the surface at 2.43 kilometers per second, or about 8,700 kilometers per hour (5,400 miles per hour).
The collision would release approximately 14.5 billion joules of energy, equivalent to about three tons of TNT.
The stage was part of the Falcon 9 rocket that launched Firefly Aerospace's Blue Ghost 1 lunar lander from NASA's Kennedy Space Center in Florida on Jan. 15, 2025.
After successfully deploying the lander, the upper stage remained in a highly elliptical orbit around Earth. Gravitational forces and pressure from solar radiation gradually altered its trajectory, resulting in its unplanned return to the Moon.
Unlike Earth, the Moon has no atmosphere to slow incoming objects.
NASA said the impact was expected to create a crater approximately 18 meters (60 feet) wide and 3.7 meters (12 feet) deep, throwing lunar dust and rock outward as ejecta.
The agency stressed that the impact posed no danger to Earth. It said a natural meteoroid carrying a similar amount of energy strikes the Moon approximately every six days, although impacts involving human-made objects are far less common.
NASA to search for impact site
NASA said its Meteoroid Environments Office would attempt to observe the collision using ground-based telescopes, but warned that lighting and weather conditions could make detection difficult.
The agency's Lunar Reconnaissance Orbiter and the ShadowCam instrument aboard South Korea's Korea Pathfinder Lunar Orbiter will also seek opportunities to photograph the site before and after the impact.
Images could take several days to become available, depending on lighting, orbital timing and the positions of the spacecraft.
NASA said data collected from the event could help scientists understand how ejecta plumes behave, study the Moon's geology and improve models used to plan future exploration missions.
A recent scientific study of 2025-010D warned that renewed interest in lunar exploration was creating a growing population of poorly tracked objects in the region between Earth and the Moon.
NASA said it remained in communication with SpaceX about the stage and its trajectory and was committed to responsible debris mitigation and disposal practices.
The agency noted, however, that controlled impacts on the lunar surface are an accepted and safe disposal method for some missions and may sometimes be the only practical option.
