![]() No, they were modeling something that happens naturally: What happens when one smaller asteroid slams into a larger one, as has happened continually over the life span of the solar system? In the paper, Ramesh and his colleagues weren’t modeling what a nuclear explosion would do to an asteroid. (Which is something NASA has some preliminary plans for.) He’s well aware it would be a lot easier just to push an asteroid out of the way. The tremendous amount of energy needed is why we wouldn’t want to blow up an asteroid to save Earth.īut Ramesh stresses that his research isn’t exactly about finding out how to destroy an asteroid on a collision course with Earth. It’s about what to expect when we visit them. This research really isn’t about destroying asteroids. Which is to say: you’d probably need to confine the force of 4,000 of the most powerful nuclear bombs into a projectile. That energy would need to be delivered with a particular momentum (that is, motion confined to a particular mass). But even then, you couldn’t just launch 4,000 nuclear weapons to destroy the asteroid. You’d need the power of 4,000 of those to annihilate a 20-kilometer-wide asteroid. The most powerful bomb in human creation had an explosive yield of 50 megatons. (This new estimate takes into account the complex interactions between small cracks that form on the asteroid’s surface upon impact, which actually make for a more impact-resistant object.) It’s also about 10 times more energy than previous estimates of what it would take to destroy an asteroid of this size. But there is some evidence that Earth has been struck by a massive 20-kilometer asteroid in the past.)Ģ00 gigatons of TNT (dynamite) contains roughly the energy equivalent of about 10 million Hiroshima-size bombs. (This is roughly double the estimated size of the asteroid or comet that is believed to have killed the dinosaurs. “We would estimate that it would take energy equivalent to about 200 gigatons of TNT to fully disrupt an asteroid with a 20-kilometer diameter,” Ramesh says. Even if there is an asteroid hurtling toward Earth, it wouldn’t make a lot of sense to launch the world’s entire nuclear arsenal at it in the hopes of blowing it up. These limitations aside, Ramesh and his colleagues determined that, well, it’s going to be very hard to destroy an asteroid - near impossible. So it’s a massively complicated process to predict how a collision will change or deform a rock in space. How quickly those numerous cracks spread and form helps determine the resiliency of the rock. When cracks form on the surface, “you suddenly you get this collective behavior of cracks all trying to really fast, all of them interacting with each other,” Ramesh says. Smashed, fissuring rocks are a complicated thing to model in a computer. If you die via asteroid, this is how it will happen ![]() But Ramesh and his colleagues were able to take the results of experiments on Earth - experiments involving very high-speed cameras studying how rocks here on Earth fissure and crack when hit with a projectile - and extrapolate them up, accounting for the low-gravity environment of the space around an asteroid. Any rock’s vulnerability to destruction is highly dependent on how many cracks, pores, and other such deformities exist on its surface. While we know that asteroids are mainly made up of iron and rock, we have limited data on their surface and interior composition. Instead, it helps us better understand what asteroids look like, and how they evolve over time as asteroids collide with one another.įirst off, there’s no way to do this sort of exercise without making some assumptions. And recently, he and colleagues published a paper in the planetary science journal Icarus that basically asked the question: What would it take to break up an asteroid? The answer to that question matters - but not so much for what it means for the future of life on Earth. Kaliat Ramesh is a professor of mechanical engineering and material science at Johns Hopkins University. How hard can it be to destroy a 10-kilometer-wide asteroid? This is a real consideration because NASA is keeping its eye on about 2,000 ”potentially hazardous” objects that come within 4,647,790 miles of Earth and are large enough to cause damage.īut also there’s this: New research suggests it’s really, really difficult to pulverize an asteroid. For one, experts in planetary protection ( a real thing) say it would be a lot simpler to just push a deadly incoming asteroid into a safer orbit. Saving the planet ought to be as easy as the press of a thermonuclear button, right? After all, that’s how Bruce Willis saved the world in Armageddon. If you were a moviegoer in the late ’90s, I wouldn’t blame you for thinking the best way to deal with an apocalyptic-size asteroid hurtling toward Earth is to blow it to smithereens.
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