Chinese scientists have proposed a drastic, albeit theoretical, method for preventing a catastrophic asteroid impact: detonating nuclear weapons deep within a threatening space rock. The strategy, detailed in a study published in the journal Space: Science & Technology, involves drilling into an asteroid and implanting a nuclear device for detonation.
Researchers from the China Academy of Launch Vehicle Technology in Beijing suggest this approach could be a crucial tool for planetary defense, especially against large near-Earth asteroids that pose a significant threat. The study aimed to provide references for engineering such defense systems, acknowledging that current methods like NASA's Double Asteroid Redirection Test (DART) might not be sufficient for all scenarios.
The DART mission, which successfully altered an asteroid's trajectory in 2022 by colliding a spacecraft with it, is effective for smaller threats. However, scientists have warned that numerous asteroids, some hundreds of feet wide, are large enough to devastate cities but small enough to evade early detection. For these city-killers, warning times could be as short as days or weeks, leaving insufficient time for conventional deflection methods.
To test the feasibility of their nuclear detonation concept, the researchers conducted computer simulations. These models examined hypothetical asteroids approaching Earth at speeds of approximately 6 miles per second. The simulations indicated that a 164-foot asteroid could be destroyed by a 300-kiloton nuclear explosion, roughly equivalent to 20 Hiroshima bombs. A larger, nearly 1,000-meter asteroid would require a 3-megaton blast.
The study also emphasized the importance of detonation depth. Placing the nuclear payload around 100 meters deep inside the asteroid was found to triple the change in the rock's velocity compared to a shallower detonation. This suggests that internal detonation could significantly alter an asteroid's course.
However, the successful execution of such a mission would require early detection of the asteroid threat to allow for the launch and transit of a spacecraft equipped with both a drilling device and a nuclear payload. Despite these challenges, the researchers stated that the study holds "profound strategic significance for enhancing humanity’s capability to respond to asteroid impact threats."
This is not the first time a nuclear solution has been considered for asteroid defense. Previously, scientists discussed the possibility of using nuclear devices against asteroid 2024 YR4, which had a remote chance of impacting Earth in 2032. While NASA has since downgraded the impact probability for 2024 YR4, the discussion highlighted the ongoing consideration of nuclear options in planetary defense strategies.