There's a few theories out there about the Moon and how it was made. It was a planetoid collided with Earth and merged and spewed out shit that turned into the Moon, or it formed else where and got stuck in Earth's gravity, or it was forming and another tiny moon slammed into the back of it, reason the dark side is rigid compared to the front.. I don't think it was any of that. I think it simply formed from the same planetary disk as Earth. (Not a new theory) The back side of the Moon, which is noticeably different, was created by a lack of material. I was staring at the Moon last night, thinking about how it's tidally locked and thinking how cool it'd be if it had a rotation. Then this idea popped in my head. Say you take a globe to represent Earth, then a perfectly round, clear sphere as the Moon. You fill the sphere with a magnetic fluid 3/4 the way up, leaving a bubble of nothing at the top. When the Earth pulls on the Moon, it's pull is strong enough to pull the material to Earth, but not enough to break the hold the core of the Moon had on it's material. So the "bubble of nothing" will face away from Earth. The area that faces Earth probably solidified first, more than likely from shit spewing out from Earth, like oxygen oxidizing the face. Meanwhile, the back side of the Moon is still sloshing around and making mountains for a few thousand more years til it too solidifies. To me, it explains why the Moon is tidally locked, how it was formed (kind of), and why the dark side is so different. I think if there was enough material to fill in the "magnetic sphere" of the Moon, it might have had a rotation.. How sweet would that have been? I was completely baked when I was thinking about it and am sure someone else has thought of the same thing, but even being sober now, it sounds good to me, lol.