Asteroids can devastate the planet in an instant – just ask the dinosaurs. Scientists at Sandia National Laboratories have now demonstrated a proof of concept method to deflect a potential Earthbound asteroid using a blast of X-rays.
Actively protecting our planet from asteroid impacts isn’t just the role of Bruce Willis anymore – NASA is taking efforts into its hands. The Sentry mission monitors near-Earth asteroids and calculates their likelihood of hitting us, and when. With enough warning, we could possibly intervene.
In 2022, NASA’s Double Asteroid Redirection Test (DART) mission rammed a spacecraft into an asteroid and successfully changed its orbit around a larger rock. But that approach is expensive, and requires a decent heads-up.
Now, the Sandia team has demonstrated a new way we could nudge an asteroid off course, which should be faster and cheaper. Setting off a nuclear explosion near the rogue rock can rapidly heat up the surface, creating vapor jets that push it away.
The researchers simulated this scenario in lab experiments, with the targets being two 12-mm samples – one made of quartz and the other fused silica. The Z machine at Sandia was used to generate soft X-ray pulses, to strike the targets. Intriguingly, these X-rays also vaporized the thin metal foils that held the samples in place, so that the mock asteroids were essentially “levitating” when the X-rays hit them.
And sure enough, the radiation heated up the samples’ surfaces quickly enough to send them into a steady free flight. Their velocities were measured to be 69.5 m (228 ft) per second for the quartz sample, and 70.3 m (230.6 ft) per second for the fused silica.
The team then used this starting point to run simulations of the physics at real asteroid scale. This nuclear deflection method, it turns out, could work on space rocks up to 4 km (2.5 miles) wide. An asteroid that big could cause chaos and destruction on a global scale. After all, it’s happened before.
Around 65 million years ago, an asteroid about 10 km (6.2 miles) wide slammed into what’s now the Yucatan Peninsula, releasing energy equivalent to 4.7 billion atomic bombs. If the shockwaves didn’t get you, you’d be done in by the continent-wide wildfires, mile-high tsunamis, months-long megaquakes, sulfuric acid rain, or the toppled food chains that come from 18 months of darkness. Around 75% of all life on Earth was wiped out.
Even a small impact can have major consequences. The meteor that exploded over Chelyabinsk, Russia in 2013 is estimated to have measured less than 20 m (66 ft) wide, and that one still injured almost 1,500 people and damaged more than 7,000 buildings with its shockwave.
The point is, an asteroid impact is something we should do everything in our power to prevent, and adding nuclear options to our asteroid redirection efforts could literally save the world one day. The Sandia team says that future experiments will be conducted on other minerals and sandy, rocky and porous samples, to simulate different types of asteroids.
The research was published in the journal Nature Physics.
Source: Sandia Labs
