> SIDE NOTE (TRIVIA YOU BOTH MIGHT BE INTERESTED IN):
>
> You wouldn't necessarily have to put really large rocks into orbit. Some
> are already orbiting the earth. According to astronomers, there are
> something like 13 non-trivial natural bodies orbiting earth. Discounting
> the moon (which is one of them) I believe the sizes range from about
> 50-2000 meters in diameter. Simply the threat of dropping a big one (say,
> 1000 meters) into an ocean should be sufficient deterrent from attack. An
> ocean drop doesn't have to be accurate, and would destroy *a lot* of coastal
> cities and lands.
Do you have further information? A citation? These rocks have an
importance beyond who gets to threaten Earth with them first; they
might be useful in the bootstrap towards large-scale space development.
-mitch
http://www.thehub.com.au/~mitch