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Fiction hypothetical about axial rotations

  1. Jan 29, 2016 #1
    Hello everyone!

    I am a fiction writer with a hypothetical question.

    For my work I have a new planet, the same size as Earth, with a moon with just a very slightly longer mean orbit (a few days). I have been reading about tidal locking which ensures that observers on the planet only see the nearest side of the moon.

    However I am asking whether it is possible to have an axial rotation that appears to 'alternate' with each cycle. For instance, for moon cycle 1 around the planet we would see the near side which would gradually rotate until cycle 2, when we see the far side which would gradually rotate until cycle 3, back to the near, and for cycle 4 we're back to the far, and so on and so forth alternating between each. I'm not talking about turning the satellite around as rapidly as a coin flip, but a kind of gradual change much like the changing lunar phases. I'm also asking about this with respect to the point of view from the planet below (so I know that a tidally-locked moon is actually rotating with respect to the planet, even though it appears 'static'). I think this would mean a kind of wobbly rotation, wouldn't it?

    Is this possible and what, if anything, could cause this? I understand it often takes a very, very long time for satellites to 'stabilise'. Perhaps this effect would be impossible to reproduce? Wouldn't it just mean having a faster rotation than being tidally locked??
    Last edited: Jan 29, 2016
  2. jcsd
  3. Jan 29, 2016 #2


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    Hi(gh) Tea, :welcome:

    Tidal locking takes a few years so set, so you have a bit of artistic freedom there :smile:
  4. Jan 29, 2016 #3
    How about 3:2 tidal locking, like Mercury? Opposite side to Sun on each orbit.
  5. Jan 29, 2016 #4
    Thank you for pointing out the Mercury example as well.
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