Lawrence Livermore National Laboratory researchers study nuclear planetary defense

Researchers at the Lawrence Livermore National Laboratory have conducted computer simulations to evaluate the effectiveness of using nuclear weapons for planetary defense against asteroids. The study, published in The Planetary Science Journal, examined whether a 1-megaton nuclear weapon could deflect or destroy a 160-meter space rock.

The findings indicate that a direct physical impact is not required for the weapon to be effective. In the vacuum of space, where traditional concussive blasts do not form due to the lack of an atmosphere, the detonation releases an intense burst of X-rays. These X-rays deposit energy into a thin surface layer of the asteroid, causing vaporization and ablation. As the surface material turns to gas and escapes, it creates thrust that pushes the rock in a new direction.

Furthermore, the radiation burst can trigger a secondary effect where force travels through the object's core, potentially tearing its physical structure apart. Digital tests showed that detonating the device at a distance of 25 meters allowed radiation to cover more of the rock, resulting in more widespread destruction than closer detonations.