The rocket’s upper stage will unintentionally slam into the moon on Wednesday, carving out a crater and sending up a plume of dust and rubble that scientists — and skygazers — are eager to observe.
Space tracking expert Bill Gray predicts an impact of 5,400 mph (8,700 kph) — seven times the speed of sound — near Einstein Crater on the moon’s sunlit western limb. With the action unfolding in the wee hours, the eastern portions of the U.S. and Canada, and much of South America should have the best views.
While scientists are not too concerned about this particular piece of space junk, it highlights the growing threat as more and more items cram into orbit.
“Things are getting crowded up there,” said Gray, who plans to view the aftermath from New Brunswick, Canada.
It was never SpaceX’s intent to hit the moon. But space experts said the crash could have been avoided if the upper stage had been nudged into orbit around the sun.
It will be the second dead rocket known to crash into the moon accidentally. A Chinese rocket segment dug out a pair of craters on the lunar far side in 2022.
Lucky for astronomers, the upcoming smashup will occur on the moon’s near side, packing the equivalent energy of three tons of TNT.
The impact flash, lasting less than a second, will probably be too dim to see, according to experts. But the stream of ejected material could stretch for several miles (kilometers) into space and remain visible to telescopes for tens of minutes.
“The gravity on the moon is low and there is no wind to blow the dust away,” said Los Alamos National Laboratory’s Benjamin Fernando, who’s encouraging observations by professionals and amateurs alike.
“Part of the reason for our interest in this event is to figure out how much of a hazard debris impacts pose to future astronauts,” he added in an email.
Fernando anticipates an impact crater nearly 90 feet across and 16 feet deep (27 meters across and 5 meters deep), too small to see from Earth but visible to spacecraft.
NASA’s Lunar Reconnaissance Orbiter and South Korea’s Danuri lunar orbiter will gather before-and-after shots of the crash scene. Danuri will stray within a mile or two (a few kilometers) of the SpaceX rocket just two minutes before impact, according to Fernando and his team.
The abandoned rocket segment — measuring some 40 feet (12 meters) and weighing around 10,000 pounds (4,500 kilograms) — hoisted two private lunar landers on Jan. 15, 2025.
One of them — Firefly Aerospace’s Blue Ghost — became the first private spacecraft to pull off a fully successful lunar touchdown. The other, Japan-based ispace’s lander, wrecked.
With meteoroids and other natural objects offering little if any warning before walloping the moon, scientists said there’s much to learn by observing well-tracked strikes by human-made objects like the one coming up. NASA hurled rocket sections and lunar modules into the moon during the Apollo era for seismic measurements. Decades later, in 2009, NASA intentionally crashed its LCROSS spacecraft and upper stage in search of ice near the lunar south pole.
With the moon as the new travel hot spot, scientists said it’s crucial to improve debris monitoring and traffic control before packs of robots and astronauts arrive.
The United States and China are racing to land astronauts on the moon in the next few years. Elon Musk’s SpaceX and Jeff Bezos’ Blue Origin are vying to provide the lander for NASA’s yet-to-be-named moonwalkers of Artemis IV, who will succeed the 12 Apollo astronauts who strolled the lunar surface.
“This impact will not be a problem,” retired astrophysicist Jonathan McDowell said in an email. “But in a future where there are long-term bases on the moon, similar impacts would be an issue and we need not to leave rocket stages in chaotic orbits of this kind.”