Despite being a favorite subject of disaster movies, bombing an approaching asteroid was touted as a very bad idea in the real world. While a nuclear bomb might destroy a smaller asteroid, nuclear destruction of a larger asteroid would only blow it into pieces. These fragments will still threaten our planet, possibly even worsening the situation, causing multiple impacts on the planet.

So is using nuclear weapons against an approaching asteroid really a bad idea? When used with the right technique, a nuclear explosion can be used as an asteroid deflection tool.

Researchers at Lawrence Livermore National Laboratory (LLNL) have created a simulation tool that can simulate what would happen if a nuclear device exploded on the surface of an asteroid. The instrument helps better understand how radiation from a nuclear explosion interacts with the asteroid’s surface, and also looks at shock wave dynamics that could affect the asteroid’s interior.

The explosive method in which radiation from the explosion vaporizes part of the asteroid’s surface, creating an explosive shock and a change in velocity in response, is called nuclear ablation.

The model could include a wide range of initial conditions, from solid rocks to debris piles, mimicking the types of asteroids we’ve recently been able to study up close. These simulations give planetary scientists more information and more options about when a space rock might someday hit Earth.

“If we have enough warning time, we could potentially activate a nuclear device and send it to an Earth-bound asteroid millions of miles away,” said researcher Mary Berkey of LLNL.

“We then detonate the device and either deflect the asteroid, keeping it intact but providing a controlled push from Earth, or disrupt the asteroid, breaking it into small, fast-moving pieces so we can miss the planet as well.”

Thanks to the Double Asteroid Redirection Test (DART) mission, in which a kinetic impactor deliberately rams an asteroid to change its orbit, scientists have learned a lot about what to do to redirect a dangerous asteroid. This new model, called the X-ray Energy Deposition Model, gives researchers the tools to leverage information from DART when exploring how nuclear ablation could be a viable alternative to kinetic impact missions.

Nuclear devices have the highest energy density per unit mass of any human technology, which could make them an invaluable tool for reducing asteroid threats, Berkey said in an LLNL news release.

But as the team wrote in their published article Planetary Science Journal“Predicting the effectiveness of a potential nuclear deflection or destruction mission depends on accurate multiphysics simulations of the device’s delivery of X-ray energy to the asteroid and the resulting material ablation.”

The team noted that the physics involved in these simulations required various complex physics packages, spanned many orders of magnitude, and were computationally quite demanding. Berkey and his colleagues set out to develop an efficient and accurate way to model nuclear deflection for a range of asteroid physical properties.

Berkey said his high-precision simulations can track photons penetrating the surfaces of asteroid-like materials such as rock, iron and ice, and account for more complex processes such as reradiation. The model also takes into account a wide variety of asteroid bodies. This comprehensive approach makes the model applicable to a wide range of potential asteroid development scenarios, they said.

If a true planetary defense emergency were to arise, LLNL’s Planetary Defense Project Manager Megan Brooke Saal said this high-quality simulation modeling would be critical to provide decision makers with actionable, risk-based information that could prevent an asteroid impact. and announced that it would save lives.