[ExI] Asteroid on track for possible Mars hit

spike spike66 at att.net
Sun Dec 23 00:52:47 UTC 2007

> -----Original Message-----
> From: extropy-chat-bounces at lists.extropy.org [mailto:extropy-chat-
> bounces at lists.extropy.org] On Behalf Of Gary Miller
> Sent: Saturday, December 22, 2007 2:32 PM
> To: 'ExI chat list'
> Subject: Re: [ExI] Asteroid on track for possible Mars hit
> Is the goal to aim for the side and detonate soon enough before impact
> with
> the asteroid to create a shockwave which pushes the asteroid enough off
> it's
> trajectory without breaking it up?...

I don't see how a superheated fusion event whizzing past would cause the
asteroid to break up.  The idea is to superheat heat one side of the rock,
so that the sublimation particles scatter in the direction of the hot side
and the rest of the rock is pushed by conservation of momentum the other
direction.  This scheme requires so much heat that a simple fission device
isn't enough, not nearly enough energy.  A fusion device is needed.  Even
then, the nuclear device is only close by for a tiny faction of a second,
like that scene at the start of every episode of the original Star Trek,
only faster. 

> That way if the course correction is not sufficient then you still have a
> mass to target and not a swarm of smaller chunks which could impact us in
> multiple collisions...

Ja, but it isn't clear to me what would cause the thing to fragment.  The
surface heats up and boils away violently.  I suppose individual fragments
could come flying off, but I don't see that as a major problem.

> Is it possible to do a shaped charge with nuclear or is that out of the
> question due to the much higher intensity of the blast...

Doubt it.  What would you use to direct a blast like that?

> Would the radioactivity created by the blast create a serious threat when
> it burnt up in the atmosphere? Gary

No the scenario I imagine would deliver almost no radioactivity to the earth
at all, for the radioactive particles continue flying into space on the same
trajectory as before the blast.  A tiny amount I suppose might imbed itself
in the rock itself and return to earth, but compared to the amount of
radioactivity from all those nucular* tests, it is nada.


*They woulda saved us all a lot of trouble had they spelled it nucular to
start with.  It isn't just the current president that pronounces it nucular,
I have heard it from a lotta nucular physicists and even biologists who talk
about the nuculus of the cell.  Nucular is easier to say than nuclear.

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