A new study favors buried explosions over Hollywood-style head-on impacts.

byMihai Andrei

July 10, 2026

in Astronomy, News

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Edited and reviewed by Zoe Gordon

Artistic depiction of an asteroid blowing up.

We’ve all seen the cheap movie version. A giant asteroid is screaming toward Earth, humanity panics, some heroics happen, and someone plants a bomb to explode the asteroid and save the planet.

The science version is more interesting.

A new study argues that if a large asteroid were discovered late on a collision course with Earth, scientists might indeed reach for detonation as a last-resort defense. But the goal would not necessarily be to “blow up” the asteroid in one dramatic boom. The smarter move, the authors suggest, may be to dig a crater first, tuck the blast into that wound, and use the asteroid’s own material to shove it away from the Earth.

Why a Simple Blast May Not Be Enough

Planetary defense has already had one successful field test.

NASA’s DART mission struck the asteroid moonlet Dimorphos in 2022 and changed its orbit. That mission used kinetic impact — a spacecraft acting like a high-speed cannonball. But DART was aimed at a small, harmless target, not a large asteroid bearing down on Earth.

Plus, time matters. Give engineers a few good years, and they can act very elegantly. A spacecraft might tug an asteroid with gravity, or another might collide with the asteroid, changing its path by a tiny bit. But if the asteroid is far enough, tiny is all you need. The earlier we spot a dangerous object, the less force we need.

But what if you don’t have time, and the asteroid isn’t far enough? Xiaowei Wang and colleagues from the China Academy of Launch Vehicle Technology explored that idea. They focused on asteroids larger than 140 meters, which fall into the highest threat category, capable of intercontinental or even global consequences.

The threat is very real. Many near-Earth asteroids remain undiscovered, including objects large enough to matter, like 2024 MK, roughly 150 meters wide, which was detected with only about 13 days of warning before it passed Earth. With 13 days, fancy deflection plans wouldn’t really work. With that kind of timeline, you’d need to take out the big guns.

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Don’t Just Blast It Blindly

The study authors built a virtual database of threatening asteroids, modeled their orbits, and ran simulations to see how spacecraft could reach them. They also used numerical simulations to estimate how different detonation strategies would affect asteroid damage and deflection. They compared two concepts: a fast direct-impact nuclear detonation and a more controlled “pre-crater” approach, where a spacecraft first digs a deeper pit before detonating.

The problem is that a bomb in space wastes energy.

That sounds odd, because nuclear explosions are enormous, and we’ve seen just how much damage they can do here on Earth. But in a vacuum, a blast doesn’t behave like a bomb on Earth. First, there’s no atmosphere to carry a shock wave across a city. Near an asteroid, much of the useful effect comes from heating, crushing, or ejecting surface material. That material flies away which makes the asteroid recoil in the opposite direction.

The key is energy coupling: how much of the detonation’s energy actually gets transferred into moving the asteroid. A standoff blast, fired at some distance, may ablate the surface and generate a push. A surface blast can do more. A buried or cratered blast can do more still, because it traps more energy against the asteroid and launches more material outward in a useful direction.

The first investigated scenario is if a spacecraft launches quickly and heads straight for the asteroid. It doesn’t slow down for a polite rendezvous; it simply slams into the target at extreme speed. The front impactor would gouge a shallow crater, and a following nuclear device detonates at or near that impact site. This approach has one enormous advantage: speed. Its mission profile is also simpler, which means it could be the best option for very short warning times.

But it comes with brutal engineering problems. At very high impact speeds, the device may not penetrate deeply. The crater may be shallow and irregular. This means the detonation timing has to be extraordinarily precise. The trailing device may have to survive debris blasted backward from the first impact. The authors describe this mode as useful for emergency scenarios, but technically demanding and uncertain.

So instead, they propose a different solution.

Dig Deeper

This plan is more patient. You start with a spacecraft that first approaches or flies with the asteroid long enough to observe it. Then it fires conventional penetrating impactors into a chosen spot, excavating a deeper crater. Only after that does the nuclear device enter the prepared pit and detonate.

Scout the rock. Pick the spot. Dig the hole. Then detonate.

In this approach, you don’t blast the asteroid apart, you shove it off trajectory.

The pre-excavation plan would not be easy. It would require a heavy launch vehicle, a space transfer platform and enough warning time to reach the asteroid before the final detonation. The authors estimate that a transfer platform capable of providing a 10-kilometer-per-second velocity increment could cover nearly all the virtual asteroid threats in their model.

Still, the researchers argue that this more complicated mission may be technically more reliable than a head-on nuclear interception. The spacecraft could inspect the asteroid. Engineers could choose the crater site. The nuclear device would not have to endure the same violent, split-second impact environment.

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This is not a call to start nuking space rocks tomorrow, but it aims to serve as an important wake-up call. The solar system is large, dark, and not fully cataloged. Hopefully, we won’t need this type of defense. But being prepared for it could prove essential. After all, Hollywood-like heroics only get you so far.