It would be unfortunate if the blast merely delayed the reconstruction of the asteroid, but I suspect that this would be unlikely. The escape velocity of an asteroid is very low if I recall, which is due to the relatively small mass of the object. Isn't it normally assumed that the asteroids are just small fragments of a much larger body that was destroyed by collisions between large planet like precursors?
My thought about water arose because the underground testing of nuclear blasts tends to look wimpish. This seems to be the result of the fact that a nuclear weapon has a relatively small amount of mass that does not carry away much momentum. The energy is enormous, but the momentum effects are minor in comparison. The water vaporizes quickly and generates a lot of pressure to act upon the plug of matter above, kind of like a large gun. I am not confident that the vaporization of normal asteroid material would generate sufficient push without a little help. The underground test containment seems to suggest the lack of extra push from standard rock based materials. Dave -----Original Message----- From: mixent <mix...@bigpond.com> To: vortex-l <vortex-l@eskimo.com> Sent: Thu, Feb 14, 2013 5:39 pm Subject: Re: [Vo]:Near earth asteroid info In reply to David Roberson's message of Wed, 13 Feb 2013 16:45:19 -0500 (EST): Hi, [snip] >A blast years in advance might spread the material in both time and space sufficiently to protect us. You have to be a little careful here. If it's too far in advance, and the blast doesn't accelerate the pieces beyond their own escape velocity, then the gravitational pull between them might bring the thing back together again before impact. It may require a bit of math to get the timing just right. BTW I don't think the water would be necessary. At the temperature of a nuclear blast, a high temperature plasma forms, surrounded by a gas. I think the plasma and the gas would provide enough pressure. However it might require a "Tsar Bomba" to do the job. BTW2 Asteroids that are "rubble collections" would obviously be better candidates than completely solid bodies, but unfortunately we don't have any say in the matter. ;) Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
