The escape velocity of the moon is actually far more than you could hit a golf ball. It’s far more than you could fire a bullet. Everything with mass has gravity, including the moon. We know that because of all the manhole covers that get stuck to Rosie O’Donnell when she goes out.
It’s far more than you could fire a bullet.
It is 7,800 fps.
Some specialized cannon (Gerald Bull’s super gun designs, and some gas guns) have already exceeded that number.
Rail guns do so regularily.
Firing projectiles form the moon to cause nuclear level impacts on the earth is completely doable.
It requires a significant technological presence on the moon.
Could an asteroid belt based system do it easier? Maybe.
Now, that post made me laugh!