Chinese scientists propose nuclear asteroid‑deflection method

Researchers led by Wang Xiaowei at the China Academy of Launch Vehicle Technology have outlined a new planetary‑defense strategy that uses nuclear explosions to stop or deflect hazardous asteroids larger than about 100 m. Their study, published in Space: Science & Technology, models two operational modes:

1. A rapid‑impact approach in which a spacecraft strikes the asteroid, creates a shallow crater and detonates a nuclear warhead inside the crater. This method is simple and can be launched quickly, but the blast energy couples less efficiently to the target.

2. A deep‑penetration approach that first drills a deep hole in the asteroid, then places a nuclear device in the cavity for detonation. Simulations show this “pre‑excavation” mode transfers far more energy to the rock, allowing the destruction of asteroids up to several hundred metres and the deflection of even larger bodies.

The authors argue that kinetic‑impact techniques such as NASA’s 2022 DART mission may be insufficient when only months of warning remain for large objects. Their nuclear‑detonation scenarios could neutralise threats comparable to the 2024 MK asteroid (≈150 m) or larger, though practical challenges such as weapon design and safe transport remain unaddressed.

The work underscores the need for robust, rapid response options in planetary defense, complementing existing monitoring efforts by NASA and other agencies.