Chinese scientists reveal most effective way to destroy doomsday asteroid

Chinese scientists claim to have found the most effective way to bury and detonate a nuclear device inside a large asteroid to prevent a potentially cataclysmic collision with the Earth.

Asteroids pose a major threat to human civilisation, having caused catastrophic environmental changes and mass extinctions in the past.

In recent years, astronomers have routinely flagged asteroids measuring tens to hundreds of metres across that have frequently made close flybys of the Earth.

A vast number of large asteroids near our planet also remain undiscovered, with warning times for potential collisions often ranging from a few days to weeks. For large asteroids that are hundreds of metres wide, methods like the one tested by Nasa’s 2021-22 Dart mission cannot achieve effective deflection within short timeframes.

To directly destroy or rapidly deflect large asteroids from their orbits, scientists at the China Academy of Launch Vehicle Technology note, nuclear detonation is the most effective method.

In extreme cases, it may be the only feasible approach for dealing with large space rocks or asteroids with short warning times, the researchers argue in a study published in Space: Science & Technology.

In the methods theorised so far, however, the impact and position of nuclear detonation on an asteroid cannot be autonomously selected.

The latest study outlines a new approach to detonate a nuclear device on a large near‑Earth asteroid.

The researchers simulated a spacecraft releasing a penetration device to excavate a deep crater on the asteroid and then guiding a nuclear device into it for detonation.

They assessed the damage caused to the rock by nuclear explosions of various sizes and burial depths.

They also examined the effects of factors like launch-vehicle characteristics and impact velocity.

The researchers found that an explosion the size of 200 Hiroshima bombs could completely blast apart an asteroid about 100m across.

They further found that burying the bomb about 30 metres beneath the surface tripled the change in the asteroid’s speed compared with a more shallow explosion.

For instance, a kilometre-scale asteroid with a deep crater detonation at 20 meters could achieve a velocity increment exceeding 30cm per second away from the Earth.

The findings provide an important foundation for planning and designing defences against large-sized or short-warning-time asteroids headed for the Earth, the scientists said, adding that nuclear blasts could be the most effective means of dealing with large asteroids with short warning times.

“This study can provide references for the engineering design of defence against large near-Earth asteroids,” the scientists wrote.