Chinese researchers have proposed an unconventional planetary defense strategy to neutralize large near-Earth asteroids by drilling deep into approaching space rocks and detonating a nuclear device inside them. The computer-simulated approach aims to maximize energy transfer and alter a dangerous asteroid’s trajectory far more effectively than surface impacts.
Scientists are confronting the reality that traditional methods of planetary defense might not be enough when time is short. While space agencies have previously demonstrated that spacecraft can alter the path of a smaller body through direct kinetic impact, researchers note those methods cannot achieve effective deflection within short timeframes for massive asteroids measuring hundreds of meters across. To address that vulnerability, a team from the China Academy of Launch Vehicle Technology in Beijing devised an unorthodox solution that relies on underground nuclear detonation.
Simulating Nuclear Blasts on Approaching Asteroids
The proposed technique involves sending a spacecraft to the targeted asteroid, releasing a penetration device to excavate a deep crater, and then guiding a nuclear device into that cavity for detonation. In a study published in the journal Space: Science & Technology, researchers detailed computer simulations that tested how hypothetical asteroids approaching Earth at a speed of 6 miles per second would react to nuclear explosions of various sizes and burial depths.
According to the simulation data, an explosion equivalent to 200 Hiroshima bombs could completely blast apart an asteroid about 100 meters across. For larger threats, a 300-kiloton nuclear explosion—equal to roughly 20 Hiroshima bombs—could obliterate a 164-foot asteroid, while a 3-megaton blast could destroy a nearly 1,000-meter space rock.
Why Subsurface Detonation Triples Velocity Changes
The depth of the nuclear payload plays a critical role in determining the mission’s effectiveness. The simulations revealed that installing a nuclear device roughly 30 to 100 meters beneath the surface tripled the change in the rock’s velocity compared to a shallower surface detonation.
For a kilometer-scale asteroid, a deep crater detonation at a depth of 20 meters could achieve a velocity increment exceeding 30 centimeters per second away from Earth. The researchers emphasized that this subsurface approach allows for a more precise point of impact and a far superior transfer of energy compared to simply hitting the exterior of the rock.
Challenges of Early Detection and Future Watchlists
Executing a subsurface nuclear intercept requires overcoming significant technological and operational hurdles. A successful mission depends on detecting potential threats far enough in advance to design, launch, and guide a complex spacecraft carrying both a heavy drilling apparatus and a nuclear payload into deep space.
Astronomers routinely flag near-Earth asteroids with warning times often restricted to a few days or weeks. While no known asteroids currently pose an immediate threat to life on Earth, historical close approaches continue to drive research into extreme countermeasures. Agencies and researchers maintain active monitoring programs to catalog space rocks, ensuring that any future doomsday scenario receives the earliest possible warning.
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