A four-tonne piece of a discarded SpaceX rocket that has been floating in space since last year is believed to have unintentionally crashed into the moon at high speed, in a collision that posed no danger to Earth but was expected to blast out a new lunar crater.
Rocket part details
The object, the height of a five-storey building, was part of the SpaceX Falcon 9 rocket that launched two commercial lunar landers, one from the US and one from Japan, towards the moon in January 2025.
The rocket body was due to hit the moon about 6.35am BST, crashing into its surface at 5,400mph (8,690 km/h). The impact was predicted to kick up a miles-long plume of lunar dust that, although illuminated by sunlight, would be difficult to spot with the naked eye from Earth.
Impact and observation
Professional and amateur astronomers using high-quality telescopes and cameras were not able to confirm the impact on Wednesday, possibly because the impact site was close to the visible edges of the moon.
US and South Korean lunar satellites will be positioned to photograph the site after impact but it may take days to receive that information.
Expected crater and Nasa's response
Nasa said the impact was expected to create a crater about 60ft (18 metres) wide and 12ft (4 metres) deep and throw dust and rock outward as ejecta.
The space agency said it would look for opportunities to image the site, with any data collected helping scientists "better understand artificial impacts and their exploration implications".
The Nasa spokesperson Jimi Russell said on Tuesday: "The impact poses no danger to Earth and Nasa scientists are planning to collect lunar data from the event and refine techniques for tracking objects in space."
Space junk and past impacts
Such rocket parts, known as stages, typically fall back into Earth's atmosphere and burn up or plunge into the ocean after boosting the rocket's payload to a precise spot in orbit.
But because the January 2025 lunar lander mission required more thrust than missions closer to Earth, the rocket's second stage remained in space, floating aimlessly among thousands of other pieces of space junk that active satellites must steer clear of.
It was not until this year that astronomers determined that the rocket stage, which had dumped its remaining fuel and could not be controlled, was on an orbital trajectory ending at the moon.
Julianna Scheiman, SpaceX's director of Nasa science and Dragon spacecraft programmes, told reporters on Monday: "What has happened is essentially a mixture of solar activity and gravity forces have put it on a path toward the moon."
Bill Gray, the creator of a widely used piece of astronomy software who published a report on the stage's impact in April, said: "This may be of some – probably minor – scientific interest, and we may learn some things from it.
"It doesn't present any danger to anyone, though it does highlight a certain carelessness about how leftover space hardware [space junk] is disposed of."
Rare lunar impacts
While tens of thousands of pieces of space junk – defunct satellites, discarded rocket parts and debris from rocket launches – are increasingly crowding Earth's orbit, human-made impacts on the moon are relatively rare.
Multiple US and Soviet spacecraft intentionally or accidentally crashed into the moon during the 20th-century space race. More recently, a Chinese rocket stage crashed into the moon in March 2022 after completing a lunar test mission. In 2009, Nasa intentionally crashed a rocket stage into the moon to study the plume of lunar material kicked up by the impact.
Several spacecraft intended to land softly on the moon in recent years have crashed instead, including Russia's Luna-25 mission in 2023 and India's Chandrayaan-2 lander mission in 2019.
Israel's Beresheet lander also crashed in 2019. Among the Israeli lander's payloads were tiny tardigrades, microscopic animals known for surviving radiation and other harsh environments, which may still be on the surface.
Mission details and aftermath
Scheiman said Nasa and SpaceX were discussing ways to prevent future lunar impacts.
The SpaceX rocket carried two lunar landers for the 2025 mission, successfully launching them towards the moon. One, named Blue Ghost, was made by the US company Firefly Aerospace and achieved a soft landing on the moon's north-eastern near side to conduct tests, including analysing lunar soil.
A second, 2-metre lander, made by the Japanese company ispace and containing a small robotic rover, crashed on final descent.
On Tuesday, SpaceX reported a smaller loss than Wall Street had expected, along with a surge in revenue, in its first quarterly report as a public company. Despite this, shares tumbled as investors remained sceptical about the company's ability to deliver on its lofty promises.
