The Moon is spiraling slowly away from Earth. What is the future of this motion?
A) The Moon will continue moving away from Earth forever, although the rate of recession will slow constantly.
B) The Moon will continue moving away from Earth forever, and the rate of recession will increase slowly.
C) When the Moon gets far enough from Earth it will become more influenced by the Sun and will eventually become a planet in a solar orbit.
D) As the Moon is receding from Earth, Earth's rate of rotation is slowing. It will eventually become tidally locked in synchronous motion with the Moon. At that point the tidal bulges will be along the Earth-Moon line, and there will be no more force to increase the Moon's orbit.

Question

Quizplus · Accepted Answer

The Moon's recession from Earth is due to tidal forces, which also cause Earth's rotation to slow. Eventually, Earth and the Moon will reach a state of tidal locking, where they show the same face to each other, halting the Moon's outward spiral.

The Moon Is Spiraling Slowly Away from Earth