Why the Moon always shows us the same face: tidal locking
30seconds
The Moon does spin. It turns exactly once for every trip around the Earth, so the same face always points our way. Walk around a chair while always facing it and you turn a full circle too.
Earth's gravity stretched the young Moon into a lemon shape, and friction in that stretched rock slowed its spin until the long axis locked onto Earth. Spin it fast below and let tides settle it.
Deep dive · 3 min
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