Question

Why do we always see only one side of the moon?

Answer 1

1. One revolution of the moon around the earth takes about 27 days. Incidentally, the moon's rotation about its own axis also takes nearly the same time.
2. The time taken for the Moon to spin on its axis is almost exactly the same as the time it takes to orbit the Earth.
3. Hence, the Moon always keeps the same side pointing our way. This is not a coincidence. Over billions of years, the Earth's gravity has forced the Moon to spin synchronously with its orbit.
4. One day on the moon is equal to 27 Earth days. So only one side of the moon can be seen from the earth.