How does moon/Earth center of gravity effect rotation and revolution?

The Earth actually undergoes nutation about the elliptical orbit as it spins around the moon.

Im wondering if this has an effect of acceleration/deceleration on the Earths orbital speed and axial speed, effecting (instantaneous) solar year and solar day.

Update:

@ignorant. Im not talking about tidal forces. Im talking about a continuous cyclic acceleration/deceleration resulting from the lunar cycle throughout the year.

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  • 1 decade ago
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    Yes, but ... the effect is pretty small.

    The effect on the length of day is very small; less than a millisecond. The Earth has a certain angular momentum from its spin, and some from its revolution around the Earth-Moon center of mass. There is very little exchange between them. That because (1) the Earth is 81.3 times more massive than the moon, and (2) the moon is so far away, and (3) the eccentricity of the Moon's orbit is only 5.5%.

    The effect on the orbit velocity ... I will have to do a little study ... <comes back 20 minutes later> ...

    The effect on speed is about +/-0.045%.

    The effect on the length of the "instantaneous" year is about +/- 2 minutes 46 seconds. This is about the time it takes for the Earth to move 1/81.3 of the Earth-Moon distance. This averages out to zero over a period of decades.

  • 1 decade ago

    The effect on the length of day is very small; less than a millisecond. The Earth has a certain angular momentum from its spin, and some from its revolution around the Earth-Moon center of mass. There is very little exchange between them. That because (1) the Earth is 81.3 times more massive than the moon, and (2) the moon is so far away, and (3) the eccentricity of the Moon's orbit is only 5.5%.

  • Anonymous
    5 years ago

    You'll need to be more specific. There are kinds of revolution that have NOTHING TO DO with gravity. Revolution means a circular motion of an object, about a central point that isn't part of that particular object. Rotation means a circular motion of an object, about a central point that resides within that object, such that each of its individual constituent particles exhibits a revolution about that point. Revolution and rotation are kinematics terms. It has nothing to do with what causes this motion. ---------------------- IF you are talking about the specific case of the motion of astronomical bodies, THEN we might be able to relate it to gravity. Remember to match the letters: A planet rotAtes on its Axis, and revOlves on its Orbit. Orbital revolution of an astronomical body, is due to the astronomical body constantly falling due to gravity towards its primary. EXCEPT, it doesn't really get close enough to crash, because it has sufficient existing tangential speed. The body is falling and continuously "overshooting its target". Rotation of an astronomical body isn't really due to anything, other than its past history of motion. The forces that enable it to rotate, instead of rip apart if the constituent particles really did travel in a straight line, are its own internal forces, that constrain it as a rigid body. ACTUALLY, interior gravity is part of this, and the structural tension forces don't really play a significant role in keeping the shape of a planet or moon. On gas giants and on stars, it is entirely gravity that keeps them together as rotating bodies. Objects need a reason to change speeds, and not to remain at the same speed. Astronomical bodies simply have no significant reason to slow down in their rotations, hence their rotations remain at the same speed relative to the constellation background.

  • 1 decade ago

    a normal earth day used to be much shorter but the moon slowed down earths rotational speed to around 24 hours, it hasn't effected the orbit much though

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