The threat of an asteroid impact has always been present, but now a team of Chinese researchers has proposed a solution that sounds like science fiction: burying a nuclear bomb beneath the surface of the space rock and detonating it to deflect or destroy it. The study, published in the journal Space: Science & Technology , details a two-phase plan that, according to its authors, could be the only viable option when warning time is short and the asteroid is too large for other methods.
The proposal has garnered global attention thanks to outlets like the South China Morning Post and has reignited the debate on the use of nuclear weapons in space. While the idea itself isn't new, the method of implementation is what's different: instead of detonating the bomb on the surface , it involves burying it at a controlled depth to maximize energy transfer. Researchers at the China Academy of Launch Vehicle Technology have conducted simulations demonstrating that this technique is far more effective than any other tested to date.
This is how the two-phase plan works
The method consists of two distinct stages. In the first, a spacecraft launches a metal projectile that impacts the asteroid at high speed, creating a crater about 30 meters deep . In the second, a second spacecraft places a nuclear charge in this crater and detonates it. In this way, the explosion is not wasted in the vacuum of space, but rather transmits all its energy directly to the rock.
The authors emphasize that this approach prevents the bomb from having to withstand the high-speed impact, as would happen if it were launched directly at the asteroid. Furthermore, by controlling the depth of the detonation, the amount of energy transferred to the object can be adjusted. According to simulations, burying the charge at 30 meters more than triples the change in velocity compared to a surface explosion.
Figures that dwarf DART
The numbers presented in the study are compelling. A 3-megaton explosion, equivalent to about 200 Hiroshima-sized bombs, would be enough to completely disintegrate an asteroid 100 meters in diameter . For smaller objects, around 50 meters in diameter, 300 kilotons would suffice—that is, about 20 Hiroshima-sized bombs.
But the most striking finding is the comparison with NASA's DART mission, which in 2022 managed to alter the speed of the asteroid Dimorphos by a mere 2,7 millimeters per second. According to the Chinese model, a 3-megaton subsurface detonation on an asteroid one kilometer in diameter would produce a change in speed of about 30 centimeters per second, some 110 times greater than what DART achieved . This makes the nuclear meteorite deflection strategy the most powerful for deflecting large objects or those with little room for maneuver.
The role of Europe and the legal challenges
While China is advancing with its simulations and planning real missions, Europe maintains a more detection-focused approach. Spain, for example, operates ESA telescopes in Cebreros and at the Calar Alto Observatory as part of the planetary surveillance and defense network for near-Earth objects. However, according to ESA documents, the European strategy is limited to observing and cataloging, without developing offensive deflection methods like the one proposed by the Chinese.
Furthermore, the use of nuclear weapons in space conflicts with the 1967 Outer Space Treaty, which prohibits the detonation of atomic devices in outer space. Although the international community could reconsider these restrictions in the event of an existential threat, there is no clear legal framework authorizing such a mission . Current protocols, such as the SMPAG and the IAWN, are not legally binding, leaving unanswered the question of who would have the authority to launch a defensive nuclear operation.
Chinese researchers acknowledge that their system would only work if the asteroid is detected years in advance—enough time to design the mission, launch high-capacity rockets, and complete the journey. Without a more comprehensive early detection network, the calculations remain theoretical. Even so, the study provides a solid foundation for future planetary defense missions and demonstrates that, when time is of the essence, nuclear power may be the only option capable of saving the planet.
