Blowing up an Earth killer asteroid with an nuclear weapon has been a mainstay of written and movie science fiction. It has fallen out of favor over the past few years because it was thought that even though the body was broken into parts, they would continue along the same trajectory and impact the Earth like a shot-gun blast instead of a bullet.
But according to an article in New Scientist, unless the nuke was sufficiently large there might be another reason that this method probably wouldn't work.
It seems that if the constituents are not accelerated apart at a high enough velocity, the pieces start to coalesce in as little as 2 hours, therefor the net impact effect would be almost identical.
The good news is that if the bomb is of sufficient yield and the asteroid relatively small, the blast would permanently disperse the asteroid's parts.
Scientist have simulated blowing up 1 kilometer asteroids and found that a bomb of 900kilo-tons yield would be sufficient. The good news is that 900 kilo-ton is a doable size however even simple math shows that even a modest increase in asteroid size requires a geometric increase in the size of the explosive device.
NewScientist via Gizmodo
But according to an article in New Scientist, unless the nuke was sufficiently large there might be another reason that this method probably wouldn't work.
It seems that if the constituents are not accelerated apart at a high enough velocity, the pieces start to coalesce in as little as 2 hours, therefor the net impact effect would be almost identical.
The good news is that if the bomb is of sufficient yield and the asteroid relatively small, the blast would permanently disperse the asteroid's parts.
Scientist have simulated blowing up 1 kilometer asteroids and found that a bomb of 900kilo-tons yield would be sufficient. The good news is that 900 kilo-ton is a doable size however even simple math shows that even a modest increase in asteroid size requires a geometric increase in the size of the explosive device.
NewScientist via Gizmodo
8 comments:
Isn't this old news. Science shows for years have been saying that the only real solution is slowly changing an asteroid's trajectory.
Bout time someone invents magic huh? At least before we have to put this reality to the test.
Marc
At first blush I had thought the same thing. However, I would really read the article for a clearer idea of where they were coming from. Yes the main stream view on this was that if you blew it up you would get a wide scatter shot effect instead of one massive blow, but the net effect would be the same amount of destruction. The difference here is no one had considered the micro gravity effect on each part nor the startling speed at which they would combine in an amalgam again. Also I found it quite startling at what point this method could work and would fail. The net results are, yes, this method would most likely fail, but the WHY is every bit as informative.
Magic has got to be a frame of reference. Think about it...any of the technology we use today, if you had a chance to whip that stuff out 2 or 3 hundred years ago would have got you an invitation to an exclusive witch burning.
The gradual course change idea sounds good. We need a large room full of high IQ persons to figure it out. I will volunteer to join the rotation to get them food and coffee as needed while they are planning this out. Just in case the EMP comes ahead of the impact, the team will need to get re-acquainted with slide rules.
Anon
Dead on...I think that the easiest and lowest tech method would be my choice. Again I am talking about the gravity tractor. The pivot point for this to work though is EARLY detection. This won't work in a few months or even a couple of years! They would need to be found decades before they become a hazard. That is where our weakness is.
What bothers me the most about the gradual method is that it divides the project into three time segments. The first is "too late" - which stretches from 2 seconds from now to a few decades. The second is "possible" which is detection between a decade or so and an impact a decade after that. The scary part is "too far away" which will allow people to say things like "let's wait and see what happens and besides why should be waste our time and resources when people in the future will figure out a better way." In the first and third we're doomed.
Marc
You state the very reason that these methods have to be funded and then given Carte-Blanche after giving them a mandate. In that course there is no public option because the money has already been spent and the mandate states that the project must be carried out.
I agree, if every time one of these monsters is discovered there is a public discussion on what should be done, nothing would be done and we would be doomed.
Is this a perfect scenario? No, but something like it has to be put into play now and fine tune as we go. And the beauty is that it doesn't require new equipment to get the ball rolling. Telescopes that have been antiquated by urban sprawl are perfect for NEOs The rocket tech can be supported with ion drives because thrust is not an issue but minute pushes on the "tractor's" mass. And with a mass driver on the Moon or one of the proto planets, cost would be much lower than competing ideas.
Post a Comment