how and why is the moon shrinking, and will moonquakes speed this up?
In: Planetary Science
Moonquakes are a result of the shrinking, not a cause.
Big rocky planets with lots of heavy radioactive elements concentrated in their cores like Earth and Venus generate a considerable amount of heat from the radiodecay. Despite being billions of years old, their innards are still white hot.
Smaller planets and moons exhaust that supply and start to cool, and when things cool they contract.
The moon didn’t start with much of a core to begin with so it has cooled dramatically and shrunk considerably over the millennia. It’s still contracting today.
Mercury’s crust has a global “wrinkle” texture to it that’s likely a result of significant contraction after it formed and cooled down.
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