Marrying asteroid defense and asteroid mining

> From: Douglas May
> Part of Sagan's (and others) concern is that the consequences of any
> asteroid mishap could be catastrophic.

I'm not sure I share this concern. Most practical studies for 'asteroid
retrieval' specify *pieces* of asteroid about a hundred meters across for
the reason that rocks this 'small' would burn up before hitting ground
level.

Besides, wouldn't they be *breaking* into earth orbit? If the engines fail
they don't hit the earth, they'd just pass right by.

> therefore there is the risk of some space settlement arising that
> hates the Earth for it's moral decadence.

Or religious stupidity.

> If such a society could
> gain control of Asteroid moving technology, they could theoretically
> wipe us out.

The colony might be at the top of our gravity well, but it would be
dependent on so many other facilities to pose any serious threat to Earth.
Even if all of the facilities rebelled at once Earth would still dwarf their
industrial capacity. Given the time and effort involved to move an asteroid
we could probably build warships from scratch and have them at their door
before the planet was in serious danger.

John