If a 10km asteroid heads for Earth, could a 500 Megaton nuke destroy it?
This is purely theoretical, but I saw the footage of the Tsar Bomba and also the Castle Bravo detonation, the two biggest nuclear explosions ever done. To my knowledge there is no real limit in how powerful you can make a nuclear warhead, but the larger the yield the bigger it will be. So, first of all, what would be the largest nuclear warhead we could deliver into space? Is a 500 Megaton warhead possible? If so, when placed on the surface of a 10km wide asteroid, would such a detonation not completely vaporize the asteroid? Just based on the destruction seen by the Tsar Bomba (50 Megaton)?
2021-01-22T04:24:34Z
I read a lot of reaction that a shattered asteroid with roughly the same mass (surely a 500 megaton warhead would vaporize a lot of the material in a 10km asteroid. Lets also not forget what kind of power such a warhead would have. 10 times more than the Tsar Bomba. So, if the asteroid changes from one solid object of 10km into millions of smaller fragments, then yes, it causes huge damage, but Earth can then catch them better and spread the impact energy, not making it an ELE.
Anonymous2021-01-20T19:14:53Z
No, a 500 Megaton blast is not enough to unbind the gravitational potential energy of a 10km asteroid.
But if there's an asteroid headed your way, it's not a good idea to blow it up. Blowing it up does not change the energy of impact of whatever pieces have broken up. What you want to do is install a small ion rocket pushing it sideways for as long as it takes to divert its trajectory from collision with the Earth.
>>If a 10km asteroid heads for Earth, could a >>500 Megaton nuke destroy it? A couple of things... first, we'd need to know what *kind* of rock it is... is it solid iron? Is it rock? Is it rock and ice? Is it solid, or simply a collection of rocks held by it's own loose gravity?
Next, how far out is it? Is it due to hit next week? Next year? Or next century?
Sending a nuke up to collide with such a beast (this is about the size of the one that wiped out the dinosaurs) would have very little effect on a dense asteroid, like solid iron, or even just solid rock... you may melt some of it, and you may blast a few pieces off, but by and large - it's going to keep coming, pretty much intact. A rock pile may be jarred loose, especially if the warhead was able to penetrate the collection to some depth. But - given enough time, the gravitational pull of those rocks may pull themselves back together, and the threat remains. Another thought is, the further out the impact is predicted to be, the more effect a nuke may have. Knock it's course by a 1/4 of a degree, and - over a century - that course may have it *missing* the Earth. The further out the rock is, the more chance there is of that occurring.
>>This is purely theoretical, but I saw the footage of the >>Tsar Bomba and also the Castle Bravo detonation, >>the two biggest nuclear explosions ever done. Impressive devices... too bad we ever discovered how to make them... I hope someday we send every single one into the Sun.
>>To my knowledge there is no real limit in how powerful you can >>make a nuclear warhead, but the larger the yield the bigger it >>will be. Uh... that's debatable. If you're going to use it to protect Earth, then you'd likely need to build the huge mega-tsar-bomba on the moon, where you could actually lift it with a rocket... And, that would be safer too - in case the rocket were to fail, I'd rather have it fall onto the lunar surface than creating the largest dirty-bomb ever on Earth... (even hydrogen bombs have fissionable first stages.)
>>So, first of all, what would be the largest nuclear warhead >>we could deliver into space? Is a 500 Megaton warhead possible? 500 megatons is an *awful* lot... You still need a trigger with fissionable material, and you'd need to contain the tritium for a much longer period of time, which means a thicker casing, which means more mass. I'm not sure you could *build* a dependable, stable 500 mt bomb, and I have to doubt you could actually launch it.
>>If so, when placed on the surface of a 10km wide asteroid, would >>such a detonation not completely vaporize the asteroid? No... even if the asteroid was a comet - a majority of water ice - you'd break some off, but you haven't *destroyed* it's matter - it's still there. And, that matter is still on the course (or close to it) for Earth. And, here's another point... a big rock heading toward Earth might be even *more* dangerous if you break it up. Instead of one big hole in the Earth, now you have millions of impacts; you've changed a single projectile into a shotgun blast, which could be more devastating than allowing the rock to hit Earth by itself. No matter how big the explosion is - that *mass* is still going to continue on it's course.
>>Just based on the destruction seen by the Tsar Bomba (50 Megaton)? It's also important to know that the blast that destroys the landscape by such a bomb is carried by Earth's atmosphere... In the vacuum of space, there's actually very little shock wave energy transmitted - because there's no medium to carry it. You get a big flash, and that's about it. In the movie "Armageddon", they were drilling to blast it from inside - which *might* break it apart, but... it's still coming.
All the nukes on earth wouldn't phase it. Consider, Tsar Bomba and Castle Bravo were deep underground. Yea, drill a deep hole in your asteroid a 50 megaton bomb like mentioned, would shatter it to pieces. Now we have a load of smaller meteorites to deal with. Watch the movie 'Armageddon',,you get the idea.
We would not want to blue up an asteroid with a bomb. It would shatter into many pieces, and they would all hit earth. There would be a thousand impacts instead of one. The total mass would be the same.