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What would happen if the moon's orbital radius were increased?

  1. Apr 14, 2014 #1
    Relating to the synchronous nature of the moon’s rotation and orbit around the earth, what would happen if the orbital radius of the moon were slightly increased?

    I want to ignore tidal locking or gravitational gradient, and just look at it from an angular momentum perspective.

    Would the moon's rotation and orbit no longer remain synchronous? Or would they remain synchronous, but with the moon’s orbital (angular) velocity simply slowed a bit, so that we on earth would just see a different constant side of the moon than we do now? Or would the rotation and orbit both be equally slowed such that we’d still see the same side of the moon as now, just in slower orbit?

    Or in other words, would the moon's rotation (spin) and precessional orbit disassociate from each other, or would they remain tied?
  2. jcsd
  3. Apr 14, 2014 #2


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    If you ignore tidal locking, there's no particular reason why the orbital period and rotational period would stay the same. You could of course change both at once to maintain the synchronization, but you could also change either one independent of the other.
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