01
It wasn't always this way
Earth's gravity gradually slowed the Moon's rotation over hundreds of millions of years (tidal friction) until it locked into this 1:1 match.
Moon · Question
Why do we always see the same side of the Moon?
The Moon does rotate — it's not frozen in place. It just rotates exactly once per orbit, so the same face always points at Earth. Watch the red marker on the Moon's surface below to see the difference.
Tidally locked
What's simplified
Why did this happen in the first place?
02
Not unique to the Moon
Tidal locking happens throughout the solar system — many moons of Jupiter and Saturn are locked to their planets the same way.
Misconception check
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Go deeper
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Next in this series →
Earth-Moon true scale ↗
True distance and diameter ratio.
Moon
Moon phases
A different consequence of the same Earth-Moon geometry.
Scale
True Earth-Moon distance
See the real gap between Earth and the Moon, to scale.