PLANETARY SECURITYDeflecting Doom: How Sandia Research Could Save Earth from Asteroids

The most efficient way to prevent potentially dangerous asteroids from damaging or even obliterating Earth may involve a coordinated nuclear response based on extensive prior data, according to Sandia National Laboratories physicist Nathan Moore.

“To most people, the danger from asteroids seems remote,” Moore said. “But our planet is hit by BB-sized asteroids every day. We call them shooting stars. We don’t want to wait for a large asteroid to show up and then scramble for the right method to deflect it.”

His team created experiments at Sandia’s Z machine, the most powerful pulsed-power machine on Earth, to monitor the deflection of synthetic asteroids subjected to Z’s sudden shocks. These experiments also beat gravity temporarily to better simulate the reaction of asteroids floating freely in space.

The goal is to create tables detailing the reactions of asteroids of varying compositions to deflection attempts, which would provide valuable data to those responding to asteroid threats in the future.

Challenges and Preparedness
“Practice makes perfect” is a reasonable philosophy, Moore said, but there are too few large asteroids observable near Earth to gain expertise by experimentally deflecting them beforehand.

“The day after, there would be no re-dos,” Moore said.

In 2023, the National Academy of Sciences released a report calling planetary defense a national priority. An ongoing NASA sky survey deems the threats credible: There are an estimated 25,000 objects big enough to cause varying degrees of destruction that could approach Earth’s vicinity, and only about one-third of them have been detected and tracked. Many move invisibly in the sun’s glare. A relatively small arrival in 2013 created chaos in Russia; a larger one is credited with ending the epoch of dinosaurs.

X-Ray ‘Scissors’ Momentarily Beat Gravity
Responding to the need, Moore and a team of Sandia scientists developed a method to record how much change in direction, or momentum, would be imparted to mock-asteroid material when subjected to the powerful X-ray pulses generated by Sandia’s Z machine. The experiment uses a technique called X-ray scissors, which removes the skewing effect of friction and gravity for a few microseconds. This helps model the actual circumstance of redirecting an asteroid free-floating in space when impacted by a series of nuclear-intensity explosions.

That is, the force of the explosion on the mock asteroid could be scaled to predict the effects of nuclear explosions on an actual asteroid.