Could we hit a lunar installation whose location was known? With just missiles as they exist now we actually couldn't. ICBMs aren't designed to fly that distance, or achieve escape velocity in the first place, or navigate without Earth's magnetic field to guide them.
As far as blowing the moon apart or knocking it out of orbit? All the nuclear weapons in the world wouldn't do shit, assuming they got there at all. Luna is far too massive. The biggest bomb we have would be equivalent to a firecracker detonated on the roof of a small school. It wouldn't make a difference how many of these flea bites we used.
And again, nukes are designed for atmospheric detonation. The blast wave is made of superheated air and steam. That's why they blow up above ground instead of on impact. This wave is where your large-scale damage comes from. No air or water to create that wave on the Moon.
And forget about environmental damage or extinctions. You can't make nuclear winter in a place that has no winter to begin with. We couldn't choke its sky with dust because it hasn't got an atmosphere, dust doesn't so much settle slowly there as fall like rocks.
When we've spent all our fury, the Moon will look and behave pretty much the same as before: a big gray ball revolving around us. Insultingly, given the pounding it's sustained over the life of the solar system, it basically wouldn't even notice our nukes.
The question of how much effect nuking Luna would have on Terra is more interesting. Radioactive dust from the skies, that kind of thing. I'm less sure about that.
Scars Unseen said:
I've tried, but it turns out that I kind of suck at Kerbal Space Program. I'm lucky when I'm able to build something that will break orbit.
I made another planet by accident when a ship worked a little too well and broke orbit on its last drop of fuel. Radar still tracks the capsule, millions of miles away, just outside Kerbin's orbit. I felt guilty at first, but Kerbals don't seem to eat. I think the little guy is fine. One of my ambitions is to send a craft to retrieve him. Not sure how stable his orbit is, though.
I'll go back to KSP when it's less buggy. Half my ships seem to come apart despite scrupulous care taken bolting everything together. Games where you do everything right and still fail are only fun in very short bursts.