A telescope in Chile has captured evidence of the impact caused by part of a SpaceX rocket slamming into the moon while travelling at 8,690km/h (5,400mph).
The European Southern Observatory’s (ESO) Very Large Telescope observed “spectral lines” – a colourful illustration of the sodium and lithium gas – in the plume of lunar dust stirred up by the impact.
The ESO telescope recorded these “chemical fingerprints” of the plume, which were visible for five to 10 minutes, the observatory said. The plume measured a few tens of kilometres in size, according to Carl Schmidt, an astronomer from Boston University’s Center for Space Physics.
Benjamin Fernando of Los Alamos National Laboratory in New Mexico, said earlier the collision could provide valuable data for future seismic experiments, and assessing “hazards from artificial space debris impacts”. Nasa hopes to soon establish a sustained human presence on the Moon, making it critical to better understand space debris in lunar orbit.
The impact occurred near the moon’s terminator line, or the boundary of its shadow between the sunlit side and its far side. Similar to past objects that have hit the moon, the rocket stage kicked up a plume of lunar dust that was briefly illuminated by sunlight, but difficult to spot with the naked eye from Earth.
Numerous satellites were orbiting the moon but none were in the right place at the right time to witness the crash, which occurred about 6.35am GMT on Wednesday. The piece of the rocket was the height of a five-storey building and weighed four tonnes.
Nasa and its Lunar Reconnaissance Orbiter probe and South Korea’s Pathfinder Lunar Orbiter are planning to take images of the site after impact, which may show the wreckage of the rocket, but it could take days to receive that information.
However, the manner in which the impact plume interacted with the sunlight allowed astronomers to glean some clues about its composition.
The sodium gas in the spectra is believed to have originated from the lunar soil, while the traces of lithium may have come from the rocket stage itself, Schmidt said.
“This observation did not go perfectly and this is a very crude analysis, but I wanted to share something quickly, and we can say more about these results in time,” Schmidt said.
Dr Sara Webb, an Australian astrophysicist at Swinburne University, said the tremendous force of the crash would have gouged out a “massive” new crater, probably 20 metres (65 feet) in diameter and five metres deep.
A vast plume was anticipated, Webb said, but “what we didn’t expect was how hard it was going to be to see this impact. We had multiple telescopes and eyes on the moon watching it, and nobody caught clear imagery or shots of it actually hitting.”
The Falcon 9 rocket from Elon Musk’s SpaceX launched in January 2025 carrying two lunar landers. Its booster returned to Earth, but the upper stage stayed in space to push the landers onward.
The rocket stage was just one of tens of thousands of pieces of “space junk” orbiting Earth. The moon routinely weathers impact from space debris including meteoroids. However, artificial collisions are less common.
With Reuters and Agence France-Presse
