The threat of an asteroid collision with Earth remains a serious concern for scientists and the space community. In a proactive effort to defend our planet, researchers at Sandia National Laboratories in the US have taken a bold step through the use of nuclear explosions as a method to deflect dangerous asteroids.
Asteroids bombard Earth every day, albeit most of them are tiny, creating what we know as shooting stars. However, as physicist Nathan Moore from Sandia Labs says: “We don’t want to wait for a large asteroid to show up and then scramble for the right method to deflect it.”
To address this, Sandia researchers have been testing the feasibility of using nuclear weapons to prevent catastrophic impacts from larger space rocks.
Rather than destroying the asteroid entirely, as seen in movies like Armageddon, the proposed method involves detonating nuclear explosions at a safe distance from the asteroid. This would vaporize part of the surface, generating enough force to alter the asteroid’s trajectory without splitting it into multiple hazardous fragments.
To conduct their research, Moore and his colleagues employed the Z machine, the world’s most powerful pulsed-power generator. This device enabled them to simulate how asteroids might respond to sudden shocks, mirroring the conditions of space. The experiments briefly negated the effects of gravity, allowing the scientists to better understand how free-floating asteroids might behave.
In these experiments, powerful X-ray pulses bombarded the surface of a simulated asteroid. As the surface vaporized, the expelled material generated a force strong enough to push the asteroid off course. This follows Newton’s third law of motion—”every action has an equal and opposite response.”
“The trick is to use just enough force to redirect the flying rock without splitting it into several equally deadly subsections advancing toward Earth,” Moore explained.
This precise approach could be particularly effective for asteroids up to 2.5 miles in diameter. Larger asteroids could also be deflected if identified early enough, giving humanity time to act.
Asteroid impacts, though rare, are devastating when they occur. The asteroid that wiped out the dinosaurs approximately 66 million years ago was roughly six miles wide. While modern humanity hasn’t experienced an event of that magnitude, the Chelyabinsk meteor that exploded over Russia in 2013 injured more than 1,200 people, proving that even smaller space rocks can cause serious damage.
To date, NASA’s DART mission has validated the use of kinetic impactors to alter the trajectory of smaller asteroids. However, this technique requires early detection of the asteroid. Nuclear-based methods, like the one Sandia Labs is investigating, could offer a viable solution when there’s less time to prepare.
Moore’s research has been published in Nature Physics.
