Nuking an asteroid will emit X-rays; what would happen next?

NASA showed us last year that we can actually redirect an asteroid by slamming a spacecraft into it. But in case that doesn’t do the trick, we’ve got another plan: let’s just nuke it.

After NASA’s DART mission successfully shifted an asteroid moonlet, a recent study explores how a nuke could steer away a rogue space rock heading towards Earth. (Even though we haven’t spotted any threats after years of searching, we’re still keeping an eye out and doing research, just to be safe.)

“If we have enough warning time, we could potentially launch a nuclear device, sending it millions of miles away to an asteroid that is headed toward Earth,” Mary Burkey, a physicist at Lawrence Livermore National Laboratory, said in a statement.

Are scientists really planning to nuke asteroids

Scientists studying planetary defense are seriously looking into the Hollywood-style idea of using a nuclear explosion to stop an approaching asteroid, just like Bruce Willis did in the 1998 movie “Armageddon.” As part of their investigation, Burkey and the team created a fresh model to predict the impact of a nuclear explosion’s intense X-ray emissions on an asteroid. When you look at it on paper, dropping a nuke on an asteroid has its perks compared to a mission like DART. The major one is energy: Nuclear bombs can generate more energy per unit of mass than any other human tech out there.

And since space launches always need to keep the mass in check, a nuclear warhead can pack a much stronger punch than any DART-style spacecraft could ever pull off.

“We would then detonate the device and either deflect the asteroid, keeping it intact but providing a controlled push away from Earth, or we could disrupt the asteroid, breaking it up into small, fast-moving fragments that would also miss the planet,” said Burkey.

Also Read: Saturn to lose its rings in 2025 only to get them back

Energy will come off in the form of X-rays

When a nuclear bomb goes off, a big chunk of its energy comes as X-rays. If one of these explosions hits an asteroid, the intense radiation can sweep over it, possibly turning any material in its way into vapor. Burkey and the team came up with their model to mimic these effects on four types of asteroid materials in various situations.

Making sure any attempt to deflect an asteroid actually steers it away on a safe path is crucial—no one wants asteroid bits heading our way and causing harm. That’s why the researchers are crossing their fingers that planetary defense scientists can use this model to better understand the situation before taking any action.

The research was published on Dec. 19 in The Planetary Science Journal.

Could nuking asteroids save our planet?

Even though the odds of an asteroid hitting Earth seem slim, no one wants to experience the fate of the dinosaurs. However, given NASA’s recent triumph with the DART mission, if we ever do face a collision course with an asteroid, it seems like our survival prospects have gotten a boost.

DART wasn’t out to blow the asteroid to bits or push it off course in the usual way. Nope, DART’s plan was to smack into it (that’s the science way of saying we crashed into it) to accelerate the asteroid. The idea was to check if we could use this method to make a menacing asteroid miss Earth by arriving too early for the planned meetup.

So, DART totally aced its mission, surpassing expectations by a mile. But what does that mean for Hollywood’s over-the-top depictions of planetary defense? Space.com caught up with Joe Cuhaj, the author of “Space Oddities: Forgotten Stories of Mankind’s Exploration of Space,” to find out if the flashy and explosive Hollywood approach would really keep us safe as Earth’s first line of defense.

From movies to reality

When delving into the scientific concepts of top asteroid movies, you can’t ignore the classic 1998 film “Armageddon.” It’s the one where a renegade asteroid is hurtling toward Earth, and a team of drilling experts ventures into space, lands on the asteroid, drills through its surface to get to the vulnerable core, and then sets off a nuclear bomb to obliterate it. It sounds way more complex compared to the straightforward DART mission, but what’s Cuhaj’s take on it?

Also in 1998, “Deep Impact” joined Hollywood’s fixation on saving Earth with nuclear weapons. Similar to “Armageddon,” scientists planned to drill into the asteroid’s core. However, when that plan flops, the crew of the spacecraft Messiah takes a different route—they fly into the asteroid, set off the remaining nuclear payload, breaking the asteroid into smaller pieces that burn up harmlessly in Earth’s atmosphere.

But in “Deep Impact,” the colossal space rock that poses a threat to the planet is just too close to divert off course. This plot twist gives Hollywood another chance to showcase its favorite nuclear solution. Despite U.S. films consistently favoring the idea of directly hitting asteroids with nukes, experts have proposed that the right approach would be to detonate bombs before the impact, generating a force that pushes the asteroid, steering it away from Earth.

Spotting asteroids is paramount

If you can’t spot an asteroid, you can’t really figure out how much of a threat it might be. And guess what? There are plenty of them out there, some big enough to wipe out cities or even cause mass-extinction events. That’s what the experts are telling Live Science. It’s a tough reality that has astronomers both worried about potential disasters and committed to uncovering as many hidden asteroids in our solar system as they can. Once we know about them, we can keep an eye on the dangerous ones and push them off course if needed. And if everything else fails, at least we can warn people in advance to move away and avoid the catastrophe.

Right now, the Sun is playing a game of hide-and-seek with a bunch of asteroids. There’s this crew of Apollo asteroids constantly whirling around, mostly hanging out way past Earth’s orbit but occasionally swinging by the Sun. Then there’s the mysterious Atens, a bunch of asteroids doing their thing mostly inside Earth’s orbit, always sticking to the sunny side of our planet.

“Aten asteroids are the most dangerous, because they cross Earth’s orbit just barely at their most distant point,” Scott Sheppard, a staff scientist at the Carnegie Institution for Science, told Live Science. “You would never see one coming, to some degree, because they’re never in the darkness of the night sky.”

Similar to your typical asteroids, most of these sneaky space rocks are probably small enough to incinerate in Earth’s atmosphere if they happen to cross our path. But here’s the kicker—there’s likely a group of undiscovered asteroids out there that are over 460 feet (140 m) in size. They’re large enough to survive the atmosphere and wreak some serious havoc if they hit, earning them the ominous nickname “city killers.”

Also Read: 99% of space junk goes unnoticed, but not for long

Asteroids could be hiding in the Sun’s glare

There could be some really huge objects out there camouflaged by the Sun’s brightness. It’s not common, but a couple of “planet killer” asteroids, each larger than 3,280 feet (1 km), might be playing hide-and-seek. These giants have the power to stir up so much dust that it could set off a global extinction event, as Sheppard highlighted.

Let’s rewind to 2022 when Sheppard and his buddies came across a planet killer playing a sneaky game of hide-and-seek with the Sun. They spilled all the exciting details in a paper in The Astronomical Journal. These researchers were hunting for asteroids hanging out near Venus. They managed to secure some time on a bunch of massive telescopes, scanning the skies for five to ten minutes every evening at twilight. And what do you know, they stumbled upon 2022 AP7 – a colossal space giant stretching a mile wide (1.5 km) with a quirky five-year orbit that basically keeps it hidden from telescopes most of the time.

Right now, 2022 AP7 only crosses paths with Earth’s orbit when we and the asteroid are on opposite sides of the Sun, so no need to worry at the moment. But here’s the catch—over thousands of years, that gap is going to shrink, bringing the two closer and closer to a potential collision that could spell disaster. And you can bet there are likely more asteroids playing the same game.

Up there in space, hundreds of miles above Earth and even beyond, space telescopes don’t have to deal with Earth’s atmosphere causing any issues. It’s a game-changer because it gives them a killer move: infrared imaging. This means they can pick up on the heat emitted by space objects, not just rely on the sunlight bouncing off them like regular telescopes do.