X-rays from nuclear blasts could defend Earth from asteroids

An asteroid hurtling toward Earth should be deflected with out a spacecraft ever touching it.

The trick is the usage of X-rays to divert the gap rock, researchers report September 23 in Nature Physics. In lab experiments, scientists heated the surfaces of free-falling faux asteroids with X-ray radiation, producing vapor plumes that pushed the objects away. Subsequent computer simulations demonstrated that X-rays emitted by a distal nuclear blast may in all probability deflect some asteroids which will well be about as wide because the National Mall in Washington, D.C., is long.

“There’s handiest one method that has been proposed that has enough energy to deflect the most threatening asteroids, the largest asteroids, or in some cases even smaller asteroids where warning time is brief,” per chance as short as a year or less, says physicist Nathan Moore of Sandia National Laboratories in Albuquerque. “The consensus world wide the planetary defense community is that X-rays from a nuclear device may be one of the important most most suitable choice in those scenarios.”

Such blasts would, in theory, occur at safe distances from Earth.

Two years ago, NASA intentionally crashed a spacecraft into asteroid Dimorphos, altering the gap rock’s orbit around every other, larger asteroid (SN: 9/26/22; SN: 10/eleven/22). It end as much as be a watershed moment for the planetary defense community. But such impacts work handiest if the asteroid is small and there’s enough time to alter its trajectory, Moore says. So he and colleagues got down to test the deflective oomph of X-rays.

The experiment began in a vacuum chamber that held a blueberry-sized mock asteroid fabricated from quartz — a mineral composed of the common asteroid component silica. The usage of the arena’s strongest X-ray generator, the team blasted the chamber for six.6 nanoseconds. The pulse vaporized the foil supports suspending the quartz, releasing the mineral into a free fall. It also heated and vaporized the falling mineral’s surface, generating a gas plume.

The expanding plume pushed on the quartz like a rocket’s exhaust, Moore says, propelling the mineral away from the X-ray source at roughly 250 kilometers per hour. Tests with fused silica produced similar results.

Evaluating the scheme’s viability for planetary defense required incorporating the experimental results into computer simulations. X-rays from a nuclear blast a couple kilometers away may in all probability deflect an asteroid of similar composition that’s as much as four kilometers wide, the team found.

The researchers hope to conduct similar experiments with iron and other asteroid constituents. “Asteroids come in a lot of flavors, fabricated from kind of a lot of styles of minerals,” he says. “It should be solely a spot to begin.”