Scientists to test crater-formation models using impact data
The empty upper stage of a SpaceX Falcon 9 rocket is believed to have struck the moon on Wednesday at approximately 5,400 mph (8,700 km/h) near the Einstein crater, BBC News reported. The impact occurred at around 07:35 BST (06:35 GMT) and produced a flash too faint to observe even through a telescope.
The stage — roughly the size of a five-storey building and weighing at least 4,000 kg — had been drifting since it launched from Florida in January 2025 on a Falcon 9 rocket carrying two lunar landers, according to BBC News. The upper stage fired to push both landers out of Earth’s orbit and onto a path toward the moon, then was left in a long, looping orbit. Over the following 18 months, gravitational forces from the Earth, moon and sun, along with pressure from sunlight, gradually nudged the stage onto a collision course.
Astronomers tracking the object determined it was headed for the moon and accelerating daily, BBC News reported. The impact near the Einstein crater — a lunar landmark more than 180 km (112 miles) wide — happened in broad daylight for much of the world.
Amateur astronomers would have had little chance of seeing the flash, which lasted a fraction of a second, though some may have observed a plume of dust stretching as far as 100 km (62 miles) that persisted for several minutes, according to BBC News. No spacecraft orbiting the moon was in position to capture the impact live, but South Korea’s Danuri orbiter had passed near the site shortly beforehand, and its team has told Korean media that any footage will be released after analysis is complete.
NASA’s Lunar Reconnaissance Orbiter is expected to photograph the impact site in the coming days, allowing before-and-after comparisons, BBC News reported. The first images and analysis are expected from powerful telescopes in the Americas, though image processing could take hours, days or weeks.
Because researchers already know the stage’s exact size, speed and point of impact, the collision allows planetary scientists to test models of how impacts excavate craters, distribute debris and generate seismic waves through the moon’s interior, according to BBC News. Understanding how much material an impact ejects could help engineers design safer landers and moon bases by estimating debris travel distances and ground shaking. Material excavated from beneath the surface may also provide data about the moon’s geology and the formation of the Earth-moon system roughly 4.5 billion years ago.
Since 1959, dozens of human-made objects have struck the moon, some by accident and many deliberately, BBC News reported. The Soviet probe Luna 2 was the first, followed by NASA’s Ranger probes in the 1960s, Apollo-era rocket stages and the LCROSS mission in 2009, which was intentionally crashed to search for water ice. The last confirmed accidental impact, in 2022, was believed to involve a booster from a Chinese lunar mission launched in 2014.
MSI previously reported that the stage was on course to strike the moon Wednesday, with space tracking expert Bill Gray predicting the impact near Einstein crater at about 5,400 mph would carve out a crater and send up a plume of dust and rubble. SpaceX rocket stage on course to strike moon Wednesday