Re: Hitting planets with comets

In message <9705071732.AA22234@unlgrad1.unl.edu> Mark Gouthro wrote:

> > >On Mon, 5 May 1997, Mikko Kurki-Suonio wrote:
> > 
> > >	So... let's apply what you said to planets... Mmmm... planet
cannot 
> > >move... so we track a hugh asteriod to drop on the planets.... we
should 
> > >get the same effect as nuclear winter or ice age on earth(If I am
wrong 
> > >feel free to correct me.). Therefor, planet is not really
defendable 
> > >either... (I think some body else mentioned drop a hugh rock on
planets 
> > >too.) 
> 
> Why not?!!!  Defense means you actually do something, like Hmm, stop 
> the asteroid before it hits the planet?

Not so easy. The enemy might have spent the last two years
carefully manouevering the asteroid onto course on the outer
edge of the solar system. It may not be detected until it is
too late to do anything about.

Even vapourising a trillion tonnes of rock just means you're
going to get hit by a trillion tonnes of plasma. You need to
push it off course, which may not be possible for a civilisation
with heavy ground defences, and few spacecraft.

> Also, NO ONE would ever drop a huge asteroid on a planet.  Planets are
> valuable!

NO ONE would ever drop a nuke on a country. Countries are valuable!

Anyway, it depends on where the asteroid lands. It could do massive
ecological damage, and bring civilisation to its knees, while the
overall biosphere remains intact - ie survivors have no problems
living afterwards other than the fact that communication, transport,
economy and organised government are practically zilch.

As Phillip suggested, Lucifer's Hammer by Niven & Pournelle is
worth reading.

-- 
Be seeing you,
Sam.