* Gravitational pull: The Earth's gravity has a stronger pull on one side of the Moon than the other. This uneven pull causes a slight bulge on the Moon, facing Earth.
* Rotation and revolution: The Moon's rotation period (the time it takes to spin once on its axis) is the same as its revolution period (the time it takes to orbit Earth). This synchronized motion means the Moon's bulge always points toward Earth.
Imagine spinning a ball on a string. As it spins, the ball always faces the same direction. The Earth's gravity acts like the string, keeping the Moon facing us.
However, you can see the far side of the Moon! We've been able to see it since the 1950s through spacecraft and satellites, like those sent during the Apollo missions.
