What happens if an asteroid the size of a 15-story building crashes into the Moon in 2032?
While the chances of the newly discovered asteroid 2024 YR4 hitting the Moon in seven years are slim – there is currently a 96% chance it won’t happen – an impact of this size would not come without consequences for the Moon, astronauts and spacecraft orbiting Earth.
A new study submitted for review by scientists with the University of Western Ontario and Athabasca University in Canada took observations from the James Webb Space Telescope of asteroid 2024 YR4 and used simulations to show how much lunar debris would be ejected out into space, sending pieces of the Moon toward Earth.
ODDS OF ASTEROID 2024 YR4 HITTING THE MOON GO UP AGAIN
After its initial discovery late last year, the asteroid appeared to have a small chance of impacting Earth, warranting international attention, and jumping to the highest asteroid threat ever given on the Torino Impact Hazard Scale. By February, more ground-based observations of the asteroid helped clear the threat to Earth, but the Moon still faces a possible impact.
On March 26, 2025, NASA’s James Webb Space Telescope captured images of asteroid 2024 YR4 that indicate the asteroid is about the size of a 15-story building. Researchers also say the asteroid’s surface may be dominated by rocks that are maybe fist-sized or larger. Asteroid 2024 YR4 is smallest object targeted by Webb to date.
(NASA, ESA, CSA, STScI, Andy Rivkin (APL) / NASA)
Earlier this year, NASA’s James Webb Space Telescope helped scientists determine that the asteroid is between 175 and 220 feet in diameter.
If Asteroid 2024 YR4 crashes into the Moon, it would create a crater more than half a mile in diameter (1 km), becoming the largest impact in about 5,000 years, according to the study. Current calculations show, if it happens, an impact would occur on the Southern Hemisphere.
The researchers said this impact would threaten satellites in low-Earth orbit for days or up to a few months, and send a fraction of the ejecta toward Earth.
The current impact corridor for 2024 YR4 (yellow) projected on a map of the Moon’s near side from Lunar Reconnaissance Orbiter.
(NASA)
Any lunar debris that makes it within Earth’s atmosphere could create a meteor shower event over the planet.
“The resulting meteor shower could last a few days and be spectacular, though the number of visible meteors somewhat muted by the low entry speed of ejecta,” the research team said.
With more than 10,000 active satellites in low-Earth orbit and more than 25,000 pieces of space junk, researchers believe an asteroid strike to the Moon could spell trouble for satellite operators.
“Given the very large total exposed area for satellites by 2032, it becomes possible that hundreds to thousands of impacts from mm-sized debris ejected by a lunar impact from 2024 YR4 will be experienced across the entire satellite fleet,” the study authors wrote. “Such impacts may damage satellites, but are small enough to generally not end active missions or cause breakups.”
Rendering of NASA’s Lunar Gateway
(NASA)
The researchers say material from the Moon could be a “serious hazard to moon-orbiting spacecraft” such as NASA’s Lunar Gateway, a planned orbiting station for astronauts, and an “even greater danger” to any lunar surface operations.
Asteroid 2024 YR4 has moved behind the Sun, limiting any new observations until 2028. Scientists say those new observations in a few years will help improve lunar impact predictions.
