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Moon's orbit

  1. Apr 24, 2013 #1
    Does the moon's orbit depends mainly on the gravity of earth and the distance between it and between earth?
     
  2. jcsd
  3. Apr 25, 2013 #2

    mfb

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    Right.
    The sun can be relevant, too, depending on your reference frame.
     
  4. Apr 25, 2013 #3
    depending on your reference frame? I think it would be rather the level of accuracy desired in your model.
     
  5. Apr 25, 2013 #4

    mfb

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    The level of accuracy is important, too.

    The earth/moon system is special:
    If you calculate the gravitational forces on the moon, the largest contribution comes from the sun. In the reference frame of the sun, the path of the moon is always bent towards the sun. To see that the moon orbits the earth, you have to look at its position relative to earth, and ignore the common orbit of earth+moon around the sun.
     
  6. Apr 25, 2013 #5
    Hmm..does this model consider the fact that the moon and the earth are non-inertial frames?
     
  7. Apr 25, 2013 #6

    Danger

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    I might be off-base in mentioning this, but it appears to me that there's another factor which is unusual in orbital situations. The moon is so huge in comparison to other satellites as to mass relative to the host planet, it's own gravity has a pretty strong influence as well (thinking of tides here).
     
  8. Apr 25, 2013 #7

    mfb

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    That is the point of my post. A simple model with just earth+moon neglects this, you get a better model if you include the sun.
     
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