Tidal locking
What is tidal locking?
The Moon spins once each time it travels around Earth. These two motions take the same amount of time, so the same side keeps facing us. This match is called tidal locking.
Try the question
What does tidal locking actually mean?
Move the Moon around Earth, then compare one spin per orbit with no spin. Follow the gold mark.
Watch for: A Moon that did not spin would show Earth every side during one orbit.
Try it with a chair
Walk around a chair while keeping your face toward it. After one lap, you have also turned your body once. The Moon does the same thing as it goes around Earth.
Questions answered
Does the Moon spin? Yes. One spin takes as long as one orbit.
Is the far side always dark? No. The far side gets sunlight too. Explore the Moon’s day and night.
Get more on this
A small wobble lets us see more
The Moon’s orbit is slightly oval. This makes our view rock a little from side to side. Over time, we can see about 59% of its surface. This apparent wobble is called libration.