Question

Which of the following is the reason why an observer sees the same side of the moon when looked up from the Earth?

• A. Moon does not rotate on its axis.
• B. The speed at which moon rotate is equal to the speed of Earth’s rotation.
• C. The time the moon takes to make one revolution around the earth and one rotation around itself is the same.
• D. The speed of rotation of Earth and the moon are the same.

Answer 1

The correct option is C The time the moon takes to make one revolution around the earth and one rotation around itself is the same.

Like the earth, the moon, also has axial and orbital motions. The moon while rotating around itself, revolves around the earth. The time it takes to make one revolution around the earth and one rotation around itself is the same. That is why, we constantly see one and the same side of the moon.