Dig a hole, bury the nuke - Chinese scientists say deep impact strategy best way to destroy dangerous asteroid

Exploding a nuclear weapon on an incoming asteroid has often been proposed as a way to deflect it and prevent a collision with Earth. A group of Chinese scientists has come up with the best method for nuking an asteroid that would yield the best results. Their paper suggests using "pre-excavation detonation", similar to what we saw in the movie Armageddon. Researchers said in a peer-reviewed study in the journal Space: Science and Technology, "Traditional kinetic impact, or long‑term force deflection methods, offer limited energy and cannot achieve effective deflection within short timeframes."

Theoretically, if the asteroid is nearly 330 feet in size, then just exploding a nuclear weapon on the surface might not cut it, they explained. The team, led by Xiaowei Wang from the China Academy of Launch Vehicle Technology, state that a two-pronged approach is required to effectively tackle a large asteroid. This requires creating a deep impact on the space rock. In the "pre-excavation detonation", a device is used to create a deep crater in the asteroid. A nuclear warhead is then placed inside it to "achieve deep detonation".

Also Read: Probe carries out record flyby of asteroid 100mn km from Earth - ‘It gave me goosebumps’

Quick method, or deep impact, which would destroy an asteroid better?

They also tested the quick mode, where the asteroid surface is struck with a nuke to create a shallow crater. They tested both modes, with the energy of a launch vehicle, the velocity of the impact spacecraft, and changes to the velocity of the asteroid as parameters. They were also tested against a "virtual threat asteroid database" with a warning window between one year and 20 years. The "pre-excavation detonation", or the deep impact method, was the clear winner. The researchers wrote that the method would see the spacecraft autonomously choosing the location for the crater to achieve deep detonation.

This method would "destroy" 330-foot asteroids and shove the smaller ones. But it could only be carried out if there is enough time. However, if such a mission is ever launched, scientists would need to take into account the composition of an asteroid. For eg, a pile of rubble might need a different approach than a solid rock. But the paper does not say anything about what would happen to the debris, and if Earth could be impacted by it.