Physics Help Forum How Do We Nuke A Comet?

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 Apr 9th 2019, 08:55 PM #21 Junior Member   Join Date: Apr 2019 Posts: 14 neila9876, Cheap, you say... Show me your math. Be diligent: DoE licenses, low pressure lab fees etc.. Make it like a business plan. Then contact me privately and I'll give you an address to send me a PDF of the prospectus. If the numbers are right perhaps I can fund it and you can run the lab test! But I still have to ask, what do you think the results might be? Got a clue?
 Apr 16th 2019, 10:37 AM #22 Junior Member   Join Date: Apr 2019 Posts: 14 What Happens When We Nuke A Comet? There is no reason to think that given random chance the next object to be discovered on its way to strike Earth will not be a large Long Period Comet. And then, given its size and the short warning we will have and even though it would give every Astronomer of the planet a stroke, our only defense will be to Nuke it. In order to have a reasonable expectation of the result and know how large the thermonuclear explosive device needs to be in order to either deflect or destroy it, we will need to know: - What is the expansion velocity of vaporized water ice in Space? - Per Mt of yield (net) what volume/mass of water ice would be vaporized? Any ideas? (KISS please. I need to explain this to politicians...)
 Apr 16th 2019, 02:15 PM #23 Senior Member     Join Date: Jun 2016 Location: England Posts: 883 I could only make guesses. The problems would be: How much of the energy from the detonation would actually be absorbed by the comet? (Given that we could estimate the amount of ice that would be converted to vapour). How would the products of the detonation spread out from the detonation site? Sideways would not produce the effect we are looking for (which is why I was suggesting multiple strikes at the same point, to try to create a funnel to direct the blast). If they were tasked to do so, I am sure that the appropriate military scientists could make reasonable estimates. However I see your chicken and egg problem. The people with the knowledge would be reluctant to chat freely with you, because they could easily fall foul of being accused of revealing classified information. If you could persuade a politician to request a paper feasibility study, this could be done for a reasonable sum. (perhaps a few thousand dollars for say a couple of hundred hours of a specialists time). topsquark likes this. __________________ ~\o/~
 Apr 16th 2019, 03:52 PM #24 Junior Member   Join Date: Apr 2019 Posts: 14 Given that only fear ever defines necessity and that such any politician's feasibility study would need to be seen as a necessity and the Astronomer 'experts' have dismissed the threat of Long Period Comets with an optimistic perception of low probability, no one is afraid of Earth impact by LPCs. My day job has been countering the delusions of the Astronomers. In the mean time... - What is the expansion velocity of vaporized water ice in Space? - Per Mt of yield (net) what volume/mass of water ice would be vaporized? I suspect that both are far lower than we would think and impact by LPCs should be seen as more fearful than impact by asteroids. Mo Fear, Mo Necessity. The theoretical math would go a long way to getting time in Sandia's Z Machine to test this empirically.
Apr 16th 2019, 07:22 PM   #25

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 Originally Posted by GaiaShield Given that only fear ever defines necessity and that such any politician's feasibility study would need to be seen as a necessity and the Astronomer 'experts' have dismissed the threat of Long Period Comets with an optimistic perception of low probability, no one is afraid of Earth impact by LPCs. My day job has been countering the delusions of the Astronomers. In the mean time... - What is the expansion velocity of vaporized water ice in Space? - Per Mt of yield (net) what volume/mass of water ice would be vaporized? I suspect that both are far lower than we would think and impact by LPCs should be seen as more fearful than impact by asteroids. Mo Fear, Mo Necessity. The theoretical math would go a long way to getting time in Sandia's Z Machine to test this empirically.
To answer the first one we would need to know a number of things: The rotation speed of the comet, how loosely or tightly the comet is packed, where the missle would hit. Those are the few I can immediately think of. If you are asking simply about how far and how fast remnents of the comet could expand then there's really no limit.

As for the amount of damage that a missle could do, if someone here knew the answer you probably would have gotten it by now. I know a fair amout of Nuclear Physics but I have never made any kind of study about yields for a nuclear warhead.

-Dan
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 Apr 16th 2019, 08:05 PM #26 Junior Member   Join Date: Apr 2019 Posts: 14 Dan, This question has only been on this University level forum for a few hours and you see No Joy already? You millennials... if the answers don't come on the first page you Google, it ain't there. You need to learn that if you stand by the side of the river long enough the bodies of all your truths will come floating by. GS
Apr 16th 2019, 11:21 PM   #27
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 Originally Posted by GaiaShield In the mean time... - What is the expansion velocity of vaporized water ice in Space? - Per Mt of yield (net) what volume/mass of water ice would be vaporized? .
Solid CO2 and solid Methane will vapourise and provide the push while the mixed in water may still be solid/liquid ...

"megaton of TNT is a unit of energy equal to 4.184 petajoules.(peta = 10 to the 15)

So a good sized H bomb(100MT) produces 4 x 10 to the 17J...

4 00000000000000000 joules

The density of comets is said to be 0.3 to 0.5 .... very soft ... a well designed , hardened missile should survive penetration , and keep it's rocket firing until the center is reached , then detonate ...

This is all about detonating in the comet's center.

 Apr 17th 2019, 08:03 AM #28 Junior Member   Join Date: Apr 2019 Posts: 14 oz93666, That may be a good approach. Maybe even a Plan A. However, I'll give you a 10 meter deep crater not the center. At -240C Comets are not that soft. The ADRC was working along those lines until NASA cut off their funding. But you are circling the problem. Let me reframe the question: Astronomers discover a 6km/100 billion ton Comet at the orbit of Jupiter. In 9 months in will impact somewhere on Earth at 60km/s imparting the kinetic energy equivalent of the 10km asteroid that impacted Chicxulub 65 million years ago and Mankind goes extinct. We need to either deflect the Comet in the main by 4,000 miles or fragment and explode those fragments at a velocity that most will not go on to strike Earth. So we Nuke it to either generate thrust for deflection or force for the sufficient dispersal of the fragments. How big a Nuke (how much yield) do we need to achieve this result? To answer 'that' question we need to know: - What is the expansion velocity of vaporized water ice in Space? - Per Mt of yield (net) what volume/mass of water ice would be vaporized? GS
Apr 17th 2019, 08:35 AM   #29

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 Originally Posted by GaiaShield Dan, This question has only been on this University level forum for a few hours and you see No Joy already? You millennials... if the answers don't come on the first page you Google, it ain't there. You need to learn that if you stand by the side of the river long enough the bodies of all your truths will come floating by. GS
I'm not quite sure what you are trying to say here, but I'm not a "millenial." And I did not get my opinions nor knowledge by Googling. I doubt that I would get anywhere doing a Google search on this so I didn't bother.

-Dan
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 Apr 17th 2019, 09:17 AM #30 Junior Member   Join Date: Apr 2019 Posts: 14 And I've spent hours on Google just looking for clues... guess I watch too much NCIS. GS

 Tags comet, nuke

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