NASA may prepare nuclear strike against asteroid threatening to crash into the moon

Neetika Walter

Once feared to have a 3.1 percent chance of striking Earth, asteroid 2024 YR4 is now more likely to collide with the moon in 2032.

Scientists are evaluating whether a nuclear strike could be the last line of defense against an asteroid that might collide with the moon in 2032.

The object, known as 2024 YR4, was discovered in December 2024 and quickly gained attention for its potential impact risk.

Initial observations suggested the asteroid, measuring about 180 feet (55 meters) across, had a relatively high chance of hitting Earth in 2032, peaking at 3.1%.

That figure was large enough to draw headlines, since an asteroid of that size could level a city if it struck our planet.

Follow-up measurements, however, sharply reduced the risk. By February 2025, the odds of the asteroid impacting Earth fell to just 0.28%, or less than 1 in 360. Instead, the main concern now is a possible collision with the moon.

If 2024 YR4 crashes into the lunar surface, it would create a massive spray of regolith—the dust and small rocks covering the moon.

This debris could increase micrometeoroid flux in Earth’s vicinity by up to 1,000 times the background levels, according to researchers. That surge of particles would raise the risk for satellites, space stations, and even astronauts in orbit.

Risks outweighing safe deflection

The researchers caution that any attempt to deflect the asteroid could create unintended hazards. Because 2024 YR4’s mass is not yet well understood, a poorly executed deflection could nudge the asteroid closer to Earth instead of away from it.

“Possibly threatening astronauts and spacecraft,” the team wrote, micrometeoroid ejecta itself is already a cause for concern. A miscalculated intervention could make things worse.

NASA does have experience with asteroid deflection. In 2022, its Double Asteroid Redirection Test (DART) slammed a spacecraft into the moonlet Dimorphos, successfully shifting its orbit around its parent asteroid, Didymos.

But unlike that demonstration, researchers stress that 2024 YR4 presents tougher challenges: limited observation time before 2032 and major uncertainty about the object’s physical properties.

Breaking rocks with nukes

Given these constraints, the study proposes a different strategy: breaking up the asteroid rather than pushing it. One possibility would be a DART-like mission designed not to deflect but to fragment the object.

If that fails, scientists suggest preparing a nuclear option. Detonating a rocket-delivered nuke on or near the asteroid could shatter it before it reaches the moon. While such an approach has never been tested in space, it remains a theoretical possibility.

The timeline would be tight. To meet the 2032 flyby, a nuclear mission would need to launch between late 2029 and late 2031. Researchers say this scenario should encourage more detailed planning now, before a truly dangerous object heads our way.

There is still a 96 percent chance the asteroid will pass harmlessly by the moon. Yet the authors argue that 2024 YR4 is a valuable case study for building planetary defense capabilities.

They call on others to estimate build times for spacecraft and design mission concepts.

The paper has been published on the preprint server arXiv.