Why only one side of the Moon is seen

The moon is tidally locked with Earth... That's why.

When the moon first solidified, it probably did spin. It's orbit was so close to the Earth, however, that it's spin was likely *slower* than it's orbit. And, the center of mass of the moon isn't in the *center* of the moon - it's shifted outward about 200 miles. Now, if the moon just rotated in space, you'd see it's surface shifting back & forth.

As the moon orbited Earth, the off-center mass was more attracted to the Earth's gravitational pull than the lunar farside; eventually, this attraction slowed the moon's rotation, until it finally kept one side always pointed to the Earth.

Same thing woul happen if you spun a dumbell weight in Earth's orbit; the attraction to one weight would be *more* than the other; the gravitational pull of Earth would slow the spin as one side was closer, until, finally, it would stop spinning, and always point one end at Earth's center of mass.

It isn't about coincidences -- it is about gravity.

The Moon is not a perfect sphere, but has its mass distributed unevenly. The Moon rotates at the same rate as it appears to revolve around the Earth because it is tidally locked.

This is the same deal as "gravity gradient stabilization" used to keep some satellites pointing toward the Earth.

it's not, only 1 side is lit by the sun.
we see the dark side often, it's just really hard to make anything out w/o light.

seriously, a little logic goes a long way on this one....
i fit always faces the sun the same way, whenever it is between the earth and the sun the dark side faces the earth, thus it is 'seen'....