Chinese rocket scientists find ‘most effective’ way to nuke a doomsday asteroid

Chinese researchers may have discovered the most effective method to destroy or alter the trajectory of a large asteroid that could threaten Earth. The proposed solution involves burying a nuclear bomb beneath the asteroid's surface and detonating it. This would be achieved through a two-step process: first, a metal penetrator would be sent into the asteroid to create a deep hole, and then a second spacecraft would deliver the nuclear bomb into the hole and detonate it.

According to simulations conducted by researchers from the China Academy of Launch Vehicle Technology in Beijing, a 3-megaton explosion, equivalent to around 200 Hiroshima bombs, could completely fragment an asteroid with a diameter of approximately 100 meters. The researchers found that planting the bomb 30 meters beneath the asteroid's surface could increase the change in the asteroid's speed by more than three times compared to a shallow explosion, making it significantly more effective in altering the asteroid's path.

This approach, reminiscent of the 1998 film Armageddon but executed by unmanned spacecraft, is argued to be more technically feasible and effective than simply crashing a bomb into the asteroid. Unlike high-speed impacts at random locations, this method allows engineers to select precise locations for bomb placement and deeper burial, avoiding the risks associated with nuclear devices surviving crashes or exploding prematurely.

Asteroids are remnants from the early solar system, orbiting mainly between Mars and Jupiter, but some cross Earth's path. In 2019, an asteroid up to 130 meters in diameter passed by Earth at a distance of 72,000 kilometers, detected only shortly before its closest approach. The only previous real-world test of asteroid deflection was NASA's Dart mission in 2022, which successfully altered the trajectory of a smaller asteroid by about 2.7 millimeters per second.

For larger objects or those detected with limited warning time, a nuclear explosion might be the most viable option, according to the Chinese team. They created computer simulations of various Earth-threatening asteroid scenarios, including different sizes, trajectories, and warning times. The results showed that a 50-meter asteroid could be completely destroyed by a 300-kiloton nuclear explosion, while a 3-megaton explosion would be sufficient to destroy a 100-meter asteroid.

The depth of burial also played a crucial role in the effectiveness of the deflection strategy. For instance, a 3-megaton bomb buried 30 meters beneath a 1-kilometer asteroid resulted in a speed change of about 30 centimeters per second, which is more than three times the speed change achieved by a 10-meter deep burial and about 110 times the speed change produced by NASA's Dart mission.

The researchers acknowledged that this concept would only be effective if a dangerous asteroid is detected early enough to design, launch, and execute the two-spacecraft mission before impact. Additionally, it would require the development of heavy-lift launch vehicles capable of delivering the penetrator and nuclear payload to deep space.

The study provides a theoretical foundation for planning and designing asteroid defense missions against large-sized or short-warning-time near-Earth asteroids, holding significant strategic importance in enhancing humanity's ability to respond to asteroid impact threats.