What's the explanation for the synchronicity of the rotation and orbiter of the moon around earth?

Answer 1

The mass in the moon is not evenly distributed. The half that faces the earth is a little heavier than the far half. That means the earth has a greater gravitational influence on the heavy side.

Undoubtedly, the moon probably rotated faster at some point in its history. But gradually, the earth's greater gravitational pull on the "heavy" side forced that side to permanently face the earth.

Answer 2

It's called tidal lock.

A good visual example is pretending a dumb-bell (a bar with two weights at either end) is slowly orbiting (and rotating) around a larger object.

Each weight comes closer to the the larger object, then moves away - but the gravitational pull slows the dumbbell as it rotates, pulling on the weight harder as it rotates away, and not pulling on the weight approaching the larger object equally.

Eventually, one weight or the other will *always* be pointed to the larger object. It'll be tidally locked.

Well, the moon is like this - it's center of mass is about 100 miles *away* from it's center, making it the equivalent of a dumbbell orbiting the Earth. Eventually, it also tidally locked, and now will *always* face one side towards the Earth.

Answer 3

It's called "tidal locking" and is due to the tides the Earth raises in the moon - the moon's rotation has been slowed due to those tides, and its rotation is the same as its orbit.
The "tidal bulge" the Earth's gravity has created in the moon helps to "lock" the moon's rotation to the same length as its orbit around the Earth.

The moon raises tides on Earth as well (the ocean tides are the "tidal bulge" in the Earth moving around the Earth as we rotate).
And the friction of the tides in the Earth are actually slowing down the Earth's rotation by a few microseconds a year.