A discarded SpaceX Falcon 9 rocket upper stage has crashed into the moon at 5,400 miles per hour, creating an explosive blast on the lunar surface.
The out-of-control spacecraft, which weighs 4,500 kilograms and measures 39 feet (12 metres) long, struck near the Einstein Crater on the western edge of the moon facing Earth.
Scientists estimate the impact produced an explosive blast equivalent to 15,000 sticks of dynamite, or three tonnes of TNT, a standard measurement unit for explosive energy.
The collision is expected to produce a flash bright enough to be observed from Earth using telescopes, though it will not be visible to the naked eye. Due to the moon's lack of atmosphere, wind and low gravity, the impact launched a cloud of dust and debris that will linger above the surface for tens of minutes.
Astronomers and international space agencies closely monitored the upper stage as it approached the moon, though researchers are still waiting to determine whether any telescopes captured images of the impact in real time.
The Falcon 9 rocket stage launched from Kennedy Space Centre on Merritt Island, Florida, in January last year. It was carrying two commercial lunar landers, Firefly Aerospace's Blue Ghost and ispace's Resilience, into lunar orbit and was not intended to crash into the moon.
SpaceX, the commercial space exploration company founded by Elon Musk, designs the lower first-stage boosters of its Falcon 9 rockets to be reusable by landing back on Earth. However, upper stages are jettisoned in orbit and left to drift, where they usually re-enter and burn up harmlessly in Earth's atmosphere.
After deploying its payload of scientific instruments into lunar orbit, the spent upper stage drifted through deep space under the gravitational influence of the moon. NASA's Centre for Near-Earth Object Studies (CNEOS), based at the Jet Propulsion Laboratory in California, confirmed the rocket was on a collision course after independent astronomers tracked its trajectory.
Crater formation and observation challenges
Astronomers expect the high-velocity impact to carve a brand new crater roughly 27 metres across and five metres deep into the lunar surface near the Einstein Crater, a large impact basin situated on the western limb of the moon.
Every year, thousands of natural meteors hit the moon and leave fresh impact craters across its cratered terrain. However, space scientists rarely get an opportunity to observe an artificial object of precisely known size, mass and velocity strike the moon.
Researchers hope to analyze the resulting flash, dust plume and crater structure to better understand the moon's long history of cosmic collisions. This data is expected to become vital as NASA's Artemis program and the Chinese National Space Administration work toward establishing permanent human bases on the lunar surface.
Because the moon lacks an atmosphere to burn up incoming space rocks, even minor asteroid fragments strike the surface at full speed, posing a severe potential hazard to future lunar habitats and astronauts.
Observing this specific collision proved significantly more difficult than expected because the crash site sat on the extreme western edge of the moon as viewed from Earth. Veteran space photographer Andrew McCarthy reported on X that he 'couldn't see a thing' during the impact window.
Two active lunar satellites, NASA's Lunar Reconnaissance Orbiter and South Korea's Danuri spacecraft, were orbiting nearby during the crash, though neither was positioned to observe the collision live. South Korea's Danuri spacecraft passed over the site shortly before impact, and the South Korean space agency told local news outlets it will release images once astronomical analysis is complete.
NASA's Lunar Reconnaissance Orbiter is scheduled to pass directly over the crash site in the coming days, which could yield high-resolution photographs of the new crater.
Accumulation of space debris on the moon
The crash marks only the second known instance of human-made space debris accidentally striking the moon. The first occurred in 2022, when remnants of a Chinese spacecraft booster struck the far side of the moon, carving out two distinct craters.
While lunar impacts pose no physical danger to human life on Earth and will not alter our planet's orbit, planetary scientists have raised growing concerns about the accumulation of human hardware on the lunar surface.
There are now roughly 3,000 human-made objects resting on the moon, with a combined total weight of approximately 190 tonnes. Experts worry this artificial material could contaminate the environment and jeopardize scientific research by altering the chemical composition of the moon's pristine surface.
Some researchers warn that human contamination might also hamper the search for extraterrestrial life by obscuring organic molecules and prebiotic material delivered to the moon by comets and asteroids over billions of years.
History of astronauts on the lunar surface
In total, 12 human beings have set foot on the moon, all of them American astronauts participating in NASA's Apollo space program between 1969 and 1972.
Neil Armstrong became the first person to walk on the lunar surface on July 21, 1969, during Apollo 11, followed shortly by crewmate Edwin 'Buzz' Aldrin. Pete Conrad and Alan Bean landed on November 19 and 20, 1969, during Apollo 12, despite their Saturn V rocket being struck by lightning twice shortly after launching from Florida.
Alan Shepard and Edgar Mitchell touched down in the Fra Mauro region on February 5, 1971, aboard Apollo 14, after launching on January 31. Fra Mauro was the original landing site designated for the ill-fated Apollo 13 mission. Later that year, on July 31, 1971, Apollo 15 astronauts Dave Scott and James Irwin landed for a three-day exploration stay that concluded on August 2.
John Young and Charlie Duke explored the surface on April 21, 1972, during Apollo 16, after overcoming a critical engine malfunction on the command and service module while in lunar orbit. The final human moonwalk took place on December 11, 1972, during Apollo 17, when Eugene 'Gene' Cernan and Harrison 'Jack' Schmitt spent days on the surface.
Before departing, Cernan etched his daughter Tracy's initials into the fine lunar soil. Because the moon experiences no atmospheric weather, wind or water erosion, her initials are expected to remain undisturbed for millennia.
