Sound like Armageddon?
Oh, just a little bit ....
I referred to Science Fiction because they work so easily with Shields and Gravity-Fields and so on. I read some of the threads on this boards and suddenly I asked myself, if you would be able to change moon gravity without physical matters like mass or velocity, what might happen?
It always sounds so easy in these stories, but even if you didn't mess up moons physics, it must have effects on earth (as you already said) and on solar system as well!
By the way: Thanks for the welcome!