Why NASA Is Quietly Preparing to Destroy an Asteroid Before It Nears Earth

In a move that could redefine planetary defense, researchers are now exploring whether humanity should preemptively detonate asteroid 2024 YR4 before it makes its closest approach in December 2032. According to NASA’s information pages, 2024 YR4 is classified as a near-Earth object and is under continuous monitoring by agencies such as the Center for Near-Earth Object Studies (CNEOS). (See NASA’s official 2024 YR4 facts page.)

The rationale: while the chances of an Earth impact are extremely low (on the order of 0.00081 per cent), the probability that it might strike the Moon is much higher, approximately 4 per cent, according to recent trajectory updates. A lunar collision, scientists warn, could eject massive amounts of debris into space, threatening satellites, lunar habitats, and crewed missions.

This debate marks a dramatic escalation from NASA’s 2022 DART mission, in which a spacecraft rammed the smaller asteroid Dimorphos, altering its orbit by 32 minutes. That mission proved kinetic impact is possible, but 2024 YR4’s uncertain mass and trajectory are pushing scientists to consider a more violent option: nuclear disruption.

What We Know About 2024 YR4: Size, Orbit, and Risk

Astronomers first detected 2024 YR4 on 27 December 2024 via the ATLAS telescope in Chile. The European Space Agency also confirms that automated warning systems flagged it soon after discovery. (See ESA’s details on 2024 YR4.) Early projections placed its Earth-strike probability above 1 per cent, triggering global attention.

Continued observations, including infrared measurements from the James Webb Space Telescope, have refined its estimated size to 174–220 feet (53–67 meters), down from earlier broader estimates of 40–90 meters. (NASA’s update blog provides this revised size and lunar‐impact probability.)

The asteroid travels in an elliptical, Earth-crossing (Apollo-type) orbit. Its trajectory calculations suggest it will make a near pass to Earth in December 2028, providing a crucial observation opportunity to tighten orbital parameters. In 2032, it is projected to approach both Earth and the Moon, with a 4 per cent lunar impact likelihood currently under study.

Its mass remains uncertain, with vast potential ranges due to unknown density and internal structure. This uncertainty is a key obstacle in planning deflection or disruption missions.

Why Merely Nudging May Not Be Enough

The DART (Double Asteroid Redirection Test) mission demonstrated that a spacecraft impact can shift an asteroid’s orbit. In that mission, the impact shortened Dimorphos’ orbital period by 32 minutes. (NASA confirmed this change.) But that success hinged on detailed pre-mission knowledge about the target’s mass, shape, and composition.

With 2024 YR4, scientists lack that precision. Without accurate mass and structure data, a kinetic nudge may under- or over-correct the path, or even fracture the asteroid unpredictably. A proposed reconnaissance mission to gather such data might be launched as late as 2028, leaving only about three years before its December 2032 closest approach, which is likely too little time for a follow-up mission.

Because of this compressed schedule and uncertainty, some researchers argue that the only reliable option is “kinetic robust disruption” or complete nuclear disruption: fragmenting the body. Hence, no large pieces pose a threat to Earth or the Moon.

How a Disruption Mission Might Work

The proposed plan involves sending two autonomous spacecraft, each fitted with 100-kiloton nuclear devices. Those warheads would navigate to the asteroid using onboard systems and detonate near or on the body, aiming to shatter it into fragments too small to pose danger. One device would act as a backup in case the primary fails.

Scientists sketch out plausible mission timelines:

Mission Type	Launch Window	Goal	Lead Time Needed
Reconnaissance	Late 2028	Characterize mass, structure	~3 years before 2032
Kinetic disruption	2027 – 2029	Break an asteroid using non-nuclear means	5–7 years of development
Nuclear disruption	2029 – 2031	Total or partial detonation	5–6 years of development

Because nuclear disruption allows for a wider margin of error, proponents believe it offers a more robust strategy, especially if lunar impact is still possible or Earth-impact risk reemerges with new data.

Simulations suggest that if an impact occurs on the Moon, as much as 100 million kilograms (≈ 220 million pounds) of lunar material could be ejected. Some models indicate up to 10 percent of that debris might be pulled toward Earth by gravitational forces, posing hazards to spacecraft or even causing meteor showers.

Possible Outcomes and Risks

• Successful disruption would fragment 2024 YR4 into tiny pieces that pose no threat to Earth or the Moon.
• Partial fragmentation could produce large fragments still on dangerous trajectories, complicating the problem.
• Missed target or misfired detonation might leave the asteroid intact or shift it unpredictably.
• Debris management is a major concern: even small fragments could damage satellites, spacecraft, or lunar infrastructure.

Challenges, Budget, Politics, and Treaties

Engineering such a mission would be enormously complex, but political and legal hurdles may be even greater. Deploying nuclear devices in space directly challenges treaties like the Outer Space Treaty of 1967 and the Partial Test Ban Treaty, which prohibit or restrict atomic explosions in outer space.

Meanwhile, NASA faces budget constraints. The 2026 U.S. federal budget proposal already threatens cuts to space missions. Convincing lawmakers to invest in a multibillion-dollar defense operation against an object with extremely low Earth-impact probability will be a tough sell.

Further, coordinating such an operation would likely require international agreement, shared responsibility, and oversight, especially given the risks of debris or miscalculation.