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Scientists mull the idea of targeting asteroid 2024 YR before it hits the moon

Preprint study's authors suggest that in one scenario, an asteroid potentially on course to hit the moon could be stopped by a nuclear blast.

This illustration shows a spacecraft using an ion beam deflector to alter the path of an asteroid in this screenshot from a NASA+ Original Documentary on Planet Defenders.
This illustration shows a spacecraft using an ion beam deflector to alter the path of an asteroid in this screenshot from a NASA+ Original Documentary on Planet Defenders.

By Stephanie Dwilson |

Scientists have been on high alert ever since asteroid 2024 YR was first discovered in late 2024, seemingly on course for a potential collision with Earth.

While that possibility has been ruled out, powerful telescopes show that the asteroid, which is about the size of a 15-story building, now has a 4.3% chance of slamming into the moon in December 2032.

In a new preprint study posted on Arxiv in September, scientists present options for space missions to 2024 YR4 in the event that a lunar impact is confirmed.

In one scenario, they consider the use of a nuclear blast to stop it.

This screenshot from NASA's Eyes on Asteroids tracker shows asteroid 2024 YR. [NASA]
This screenshot from NASA's Eyes on Asteroids tracker shows asteroid 2024 YR. [NASA]
The yellow points at the top left of this graphic show the range of possible locations of asteroid 2024 YR4 on December 22, 2032, when there is about a 4% chance it will collide with the moon. [NASA/JPL Center for Near-Earth Object Studies]
The yellow points at the top left of this graphic show the range of possible locations of asteroid 2024 YR4 on December 22, 2032, when there is about a 4% chance it will collide with the moon. [NASA/JPL Center for Near-Earth Object Studies]

While the asteroid's impact with the moon would not endanger life on Earth, it would kick up a lot of debris from the moon’s surface (lunar ejecta), the study's authors say.

This could increase the amount of micrometeoroid debris in low Earth orbit by about 1,000 times above background levels, they say, noting that such a sudden change could potentially endanger astronauts and spacecraft.

A potential collision

The authors address several potential methods for dealing with the asteroid.

They look at flyby and rendezvous reconnaissance, deflection, and robust disruption, examining rapid-response and delayed launch options through 2032.

"We evaluate chemical and solar electric propulsion, various launch vehicles, optimized deep space maneuvers, and gravity assists," the study's authors say.

"Re-tasking extant spacecraft and using built spacecraft not yet launched are also considered."

The asteroid’s size would make its impact big enough to destroy a city.

While scientists briefly thought it had a 3.1% chance of hitting Earth, with better data they in February determined it only had 0.28% chance of hitting Earth. They now put the chance of a collision with Earth at effectively zero.

But the chances that it could hit the moon have risen to just over 4%.

To prevent a lunar collision, a nuclear blast might be the only safe option, the study's authors suggest.

They note that trying to divert the asteroid could be risky, as its exact mass is not known, and nudging it off course might accidentally push it closer to Earth.

Deflection missions were assessed and appear impractical, they concluded.

"However, kinetic robust disruption missions are available with launches between April 2030 and April 2032," they noted. "Nuclear robust disruption missions are also available with launches between late 2029 and late 2031."

'Robust disruption'

The authors suggest that breaking up the asteroid with a nuclear explosive is one possible viable option (which they refer to as a "robust disruption.") This approach has never been tested, however, so it comes with risks.

But a decision needs to be made quickly if any of these approaches are to be taken, they write.

They suggest that radar simulations, if done soon enough, could help researchers modify hardware to ensure a successful nuclear disruption.

If existing spacecraft are repurposed for rapid reconnaissance, they say, scientists can get in-space observations faster and better assess the situation.

"The best reconnaissance mission options launch in late 2028, leaving only approximately three years for development at the time of this writing in August 2025,” they write.

The authors note that in February 2026, the James Webb Telescope will have a chance to study 2024 YR again, which might give them a better idea of just what the chances are that the asteroid could hit the moon.

But if those observations aren’t achieved, another opportunity won’t arrive until June 2028 via ground-based telescopes, leaving even less time to act.

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wow we really are in the sci-fi age