On the evening of December 22, 2032, a modest-sized asteroid called 2024 YR4 could potentially slam into the Moon, and the collision could produce a meteor shower unlike anything seen in living memory. The rocks lighting up our skies wouldn’t be space debris from a distant comet or asteroid, but fragments of the Moon itself — blasted free by a cosmic bullet traveling 13 kilometers per second. Vital space satellites and even astronauts onboard the International Space Station may be at risk.

The asteroid is about 60 meters across, roughly the size of a sports arena. It was first flagged by astronomers earlier this year when it briefly raised alarm for its 3% chance of striking Earth. That risk has since dropped to nearly zero. But the Moon, Earth’s closest celestial companion, is still in the crosshairs, with new data from the James Webb Space Telescope bumping the odds of a lunar strike to 4.3%.

That might not sound like much. But in cosmic roulette, it’s a real shot — and just in time for the holidays.

A Rare Lunar Event — and a Vivid Meteor Shower

If 2024 YR4 hits, it will create a blast equivalent to 6.5 million tons of TNT. The resulting crater would stretch about a kilometer across — bigger than almost any the Moon has seen in the past 5,000 years.

“If 2024 YR4 strikes the Moon in 2032, it will (statistically speaking) be the largest impact in approximately 5,000 years,” wrote the study’s authors, led by planetary scientist Dr. Paul Wiegert of the University of Western Ontario.

But the real spectacle won’t be the hole in the Moon — it’ll be the fallout.

A Mark Beyond the Moon

The impact could launch more than 10 million kilograms of lunar rock into space. And some of that debris, ranging in size from grains of sand to marbles, may make its way to Earth just days later. Most of it will burn up in the atmosphere. But not all of it.

Using simulations based on actual trajectory data and the Moon’s orbital orientation, Wiegert’s team found that depending on where 2024 YR4 lands, as much as 10% of the Moon’s ejected material could reach Earth’s skies. In some scenarios, the particles would start arriving just three to five days after impact.

“The resulting meteor shower at Earth could be eye-catching,” the researchers wrote. Because lunar rocks are ejected at lower speeds than typical meteors, the streaks they produce might be longer and slower — more like ghostly arcs than flashes. A few could even survive the fiery descent.

Not Just a Pretty Light Show

The risk to humans on the ground is minimal. But for satellites orbiting Earth — and possibly for astronauts — this lunar fallout poses a real concern.

“A centimetre-sized rock travelling at tens of thousands of metres per second is a lot like a bullet,” Dr. Wiegert told Agence France-Presse. Even small fragments could pierce satellite shielding, and with thousands of new satellites expected in orbit by 2032, the chances of a collision only increase.

By analyzing likely trajectories, the team estimated that Earth-orbiting satellites might experience what amounts to several years’ worth of micrometeoroid impacts, crammed into just a few days. “This added impact exposure will result in accelerated degradation of Earth-orbiting satellites,” they noted in their paper. For megaconstellations like Starlink, with their large cross-sectional areas, the event could mean hundreds or thousands of hits by millimeter-sized debris.

This debris won’t likely destroy spacecraft and satellites, but it adds wear and tear. In rare cases, a lucky — or unlucky — piece of rock could disable a satellite or trigger a cascade of debris collisions.

Moon-orbiting missions like NASA’s planned Lunar Gateway could also be vulnerable. And lunar surface habitats or instruments — if any are operational by then — would be directly in the path of ejecta raining back down.

An Event to learn From

“This event would highlight the need to expand planetary defense to include cis-lunar space,” the researchers wrote. In other words, our eyes shouldn’t just be on Earth.

For scientists, the event would offer an unprecedented opportunity. Lunar impacts of this magnitude don’t happen often — and they almost never occur where we can observe them closely. If it does happen, telescopes on Earth and in orbit could track the event in real time. Researchers could study how debris travels from the Moon to Earth, observe crater formation from afar, and possibly even recover particles from the atmosphere days later.

Even the meteor shower itself would be scientifically valuable. Lunar ejecta would be unmistakably different from most other space dust. And because it comes from a known source at a known time, it would present a rare, controlled experiment.

There’s even a chance, albeit slim, that some larger rocks could survive all the way to the ground. These would be lunar meteorites with a clear timestamp that could offer insights into the moon that would have otherwise been out of reach.

A Long Wait — and an Uncertain Outcome

There’s no guarantee the asteroid will hit the Moon. The odds are still just over 4%. And no one will know more until the asteroid swings back into view in 2028. It’s currently too far away to track in detail.

But the fact that this scenario is plausible at all has scientists paying close attention. NASA’s planetary defense program, built in part to anticipate threats like this, has focused mostly on Earth-bound risks. A Moon impact—while not catastrophic—could still cause problems in our shared space neighborhood.

“A planetary defense framework focused solely on Earth may be too narrow,” the authors argue.

Back in 2022, NASA deliberately crashed its DART spacecraft into an asteroid to test our ability to deflect a real threat. That mission was a blasting success for planetary defense. But 2024 YR4 presents a different kind of warning and challenge. Perhaps one day, a similar mission will be launched, not to defend Earth but to protect our Moon.

The findings have so far been published in the pre-print server arXiv (not peer-reviewed) and are under review by the Astrophysical Journal Letters.