Planetary Defense: Scientists Plan to Nuke “City Killer” Asteroid Headed Towards the Moon

An asteroid that was previously on a collision course with Earth is now headed towards the moon. A team of NASA researchers has an extreme solution: blast it with nukes before it makes contact. Here’s why the scientists are proposing this violent tactic. 

The “City Killer” Asteroid

The asteroid was named 2024 YR4 and became widely known when it appeared that the asteroid had a high chance of colliding with Earth. It was first reported in December of 2024 and was dubbed a “city killer” due to its high risk of collision.

Previous Threat to Earth

NASA uses a Sentry Impact Risk Table to assess the likelihood of objects entering Earth’s orbit and potential collision situations. In early 2025, Asteroid 2024 YR4 was the only space object with any chance of hitting Earth, and the probability of impact rose to a record-breaking 3.1%, which initially concerned scientists.

Where Did the Asteroid Come From?

Scientists have discerned that the asteroid came from the central region of the main asteroid belt and was likely pushed into Earth’s orbit by Jupiter. Based on the composition of the asteroid, it appears it migrated into its current orbit over a long period of time.

The Asteroid’s Composition

The asteroid has a rocky silicate-rich exterior and spins in the opposite direction to its orbit. The rocky exterior provided clues to experts on which part of the asteroid belt it originated from.

A New Destination and a New Threat

By February of 2025, Scientists had concluded enough studies of the object to assert that the risk of collision with our planet had significantly decreased to almost nothing. Now, however, it appears the asteroid is on a trajectory towards the moon, which could have dire consequences. 

Why Scientists are Concerned

The asteroid is approximately 300 feet long, which is the size of a 10-story building. Its sheer size and rate of movement are what concern scientists about its impact. It is the reason that when it was hurling towards Earth, it gained the name “city killer” as it had the ability to wipe out an entire city.

Odds of Impact Increase

Concern among astronomers is increasing as the odds of the asteroid making contact with the moon keep rising. According to NASA’s Center for Near Earth Object Studies, the odds of the asteroid making contact increased from 1.7% to 3.8% in one month and then increased again to 4.3%.

What Happens if a Collision Occurs?

If the asteroid were to hit the moon, there are several worrisome potential consequences. For one, the large impact could shake so much debris into the atmosphere that it would disturb Earth’s satellites. Thankfully, however, NASA has confirmed that the impact would not be able to alter the moon’s orbit around our planet.

Why an Extreme Solution is Needed

While it may sound extreme, nuclear weapons may be the best solution to save the moon from impact. At the current trajectory, there would not be enough time to gather critical information about the asteroid (like its exact weight) and build a spacecraft that would successfully knock the asteroid off its current trajectory.

Nuclear Weapons May Be the Solution

Launching a blast of nuclear bombs at the asteroid would not require as much exact calculation to make an impact and disturb the asteroid’s trajectory. The researchers argue that this would take much less time, and at the current trajectory, scientists will need to take action between 2029 and 2031.

Proof of Concept

While nuclear weapons may be necessary to completely destroy this asteroid, NASA did perform a test in 2022 that showed that it was, in fact, possible to “redirect” an asteroid off of its current course. The test was called DART (Double Asteroid Redirection Test), and it involved running a spacecraft into the asteroid to nudge it off its course.

Have Nukes Been Used to Deter Asteroids Before?

While this method has not been used to deter asteroids yet, using this kind of weaponry as a method of planetary defense is becoming a rapidly growing field of study. That being said, there are several political, technical, and legal hurdles that scientists will have to jump through.

Looking Forward

NASA scientists and other astronomers are continuing to work together to assess the threat level and best solution to throw the asteroid off course if it continues to hurtle towards the moon. Thankfully, there is no longer a threat of collision with Earth at this time.

Other Asteroids at Risk of Collision

While it appears Earth is safe from this asteroid for now, it isn’t the only collision risk for our planet. Scientists recently identified a cluster of asteroids within Venus’ orbit that could have future encounters with our planet.

Venusian Co-Orbital Asteroids

In findings published in Astronomy & Astrophysics, astronomers collected studies on a group of celestial objects that came to be known as Venusian Co-orbital Asteroids. In other words, asteroids that are in Venus’ orbit.

They’re Hidden From Us

Interestingly, these asteroids are hidden from our view here on Earth. From our perspective, they are close to the Sun’s glare, which makes it impossible for telescopes to detect them. They are in what we would call a “blind spot”, making them exceedingly difficult to monitor.

Threat to Earth

These asteroids are much larger than Asteroid 2024 YR4, which measures about 300 feet in diameter. Venus’ asteroids are closer to 300 meters long in diameter, which could cause complete continental destruction if impact were to occur.

How Many Are There?

There have been about 20 asteroids identified in the cluster, but that is not to say there may not be more that are hiding in the blind spot, close to the sun.

Concern Over Orbital Shifts

While they are not currently on a collision course with our planet, over the course of thousands of years, the orbits may shift and could provide opportunities for some of them to cross paths with Earth’s orbit, which would be detrimental.

Better Look at the Sun

In order for the experts to gain a better understanding of the asteroid cluster and its orbits, they need to be able to take a closer look at the Sun to track their movements. Space-based observatories would make this possible.

Conclusion

Since asteroids can join Earth’s orbit at virtually any time, the idea of planetary defense is growing increasingly more interesting to experts. There may be invisible threats that are not even on our radar yet, and having a planned line of defense against these unwelcome visitors may be critical.