Question

Why are we able to see only one side of the Moon?

• A. Because the size of the Moon is small compared to the Earth.
• B. Because the Moon's rotation period is equal to its revolution period.
• C. Due to the reflection of the moonlight.
• D. Because the rotation of Earth and the rotation of the Moon takes equal time.

Answer 1

The correct option is B

Because the Moon's rotation period is equal to its revolution period.

The Moon revolves around Earth as it rotates on its own axis. The time period to complete one rotation on its own axis is equal to the time taken to complete one revolution around Earth. This makes the Moon tidally locked, i.e., the part of the Moon visible from Earth remains the same. Hence we are able to see only one side of the Moon.