Physical Characteristics
Gravitational forces between the Earth and the Moon cause tides.
The majority of the far side was completely unknown until the Soviet spacecraft Luna 3 photographed it in 1959
There is no "dark side" of the Moon; all parts of the Moon get sunlight half the time.
There may be water ice in some deep craters near the Moon's south pole which are permanently shaded, at the north pole as well.
The Moon's crust averages 68 km thick.
Below the crust is a partially molten mantle and probably a small core.
Moon's center of mass is offset from its geometric center by about 2 km in the direction toward the Earth.
The crust is thinner on the near side.