No Bomb Powerful Enough To Destroy an On-Rushing Asteroid, Sorry Bruce Willis 352
coondoggie writes "Maybe it's the doom predictions about the end of the Mayan calendar this year, or maybe these guys are obsessed with old Bruce Willis movies. Either way a class of physics students from the University of Leicester decided to evaluate whether or not the premise of Willis' 1998 'Armageddon' movie — where a group of oil drillers is sent by NASA to detonate nuclear devices on an asteroid that threatens to destroy Earth — could actually happen. The students found it would take a bomb about a billion times stronger than the biggest bomb ever detonated on Earth."
not about destroying (Score:5, Insightful)
is it me or did the class get it wrong, it was never about destroying an asteroid, it was about splitting it up in pieces or nudging it out of the earth direction
Bruce still has a shot (Score:3, Insightful)
"The biggest bomb ever detonated on earth" is a damn sight smaller than the biggest one ever built... Just sayin'.
Don't forget who directed the movie (Score:5, Insightful)
Plot points based in hard science aren't exactly Michael Bay's MO...
Re:Nothing new (Score:4, Insightful)
You drill a hole in the asteroid and insert a nuclear device. Do not seal the hole. Explode the device. You get a volcano. Asteroid's material becomes the reaction mass (largely gases and small rocks.) Relatively small mass * relatively high speed = decent momentum. Repeat until satisfied. Call this project "Noiro."
Re:not about destroying (Score:4, Insightful)
Also why not do a case study for thresholds where the bomb might be useful. An asteroid that threatens the planet may not be stopped, but something that could wipe out a metropolitan area and cause trillions of dollars of damage might be a size that could be. An asteroid on that scale may do less or no damage if it could be broken into small enough pieces before it hits the atmosphere.
Also anyone remember that Deep Impact mission with the copper slug slammed into an asteroid some years back? That inert chunk of metal also happened to be very close to the volume and mass of a common nuclear warhead in the U.S. arsenal. (Looking at those numbers, it doesn't appear too random.) It seems somebody was seriously considering the idea.
Re:Bruce still has a shot (Score:5, Insightful)
Actually, there was a real, sensible (as things go in the field of nuclear deterrent) reason for them: The USSR did not at the time have anything that could deliver a payload with precision. Plus, they used big and slow bombers, which made it possible to intercept them. Thus, they employed a lesson from Ken Thompson in the future: "When in doubt, use brute force". :)
The design was not scaled down as such - it was a 100MT bomb; they simply substituted lead for U-238 in the tamper.
Re:not about destroying (Score:5, Insightful)
Indeed drilling a hole to the center of the asteroid and blowing it from inside is inefficient and stupid. The best way would be to aply force to the side of the asteroid, so its trajectory would change to non-coliding with earth.
I'd think that for a small body, the two are the same. A reason for drilling a deep hole first would be to get a much more precise vector for pushing the asteroid.
Sure, you lose a lot of energy that way, but you lose an awful lot with a surface blast too, where more than half the blast force won't hit the asteroid at all. There's no way of making a nuclear explosion into a shaped charge without using the environment to shape it.
Re:not about destroying (Score:5, Insightful)
That wouldnt be a good movie.
Its either.
A. Sir! we got a astroid that is going to hit earth with in 20 years.
Good find private, now send up the ION maker and point at it for the next 15 years, that should move it away to safely pass by
OR
B. Sir we got a asteroid that will hit us in the next few months
Good find private, we will nuke the bastard, but first we must make some realy cool ships, get a few heroes and they can go drill the hole in the asteroid and really get it good.
A is good if it realy happens, B is good for the movie theater...
Re:not about destroying (Score:5, Insightful)
What they mean is "break an asteroid the size of Ceres into two pieces, both of which would miss the planet, assuming the asteroid (the size of Ceres) were only noticed heading towards Earth at about the time the guys in the movie noticed it".
And while it is no doubt true that it would take that much energy to break Ceres in half if it were that far away, this says nothing at all about more, shall we say, "realistic" scenarios involving asteroids small enough to actually get that close before we notice them.
Or for that matter, asteroids that big as far away as we'd notice them....
Comment removed (Score:4, Insightful)
Re:not about destroying (Score:5, Insightful)