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Elliptical Orbits

  1. Nov 6, 2009 #1
    Why revolving bodies have their orbits elliptical and not perfectly circular (please correct me if I am wrong)?
  2. jcsd
  3. Nov 6, 2009 #2


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    Is there anything in nature that is perfectly circular? Perfect circles exist in math only.
  4. Nov 6, 2009 #3

    Vanadium 50

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    Because ellipses (technically, conic sections) are the trajectories of particles in a 1/r potential. If gravity had a different relation of force vs. distance, there would be different shaped orbits.
  5. Nov 6, 2009 #4
    Just for a comparison, and I actually wonder about it: Celestial bodies revolve around other objects due to gravity, does the same apply to Saturn's rings too (or is it just like Saturn's atmosphere)?

    I was looking for an example for a circular orbit. Saturn's rings are a set of large number of bodies and they together form a perfect circular orbit.
  6. Nov 6, 2009 #5
    If a satellite were in a circular orbit, but then it gets knocked by a meteoroid so that the direction of its tangential velocity is no longer exactly perpendicular to the direction of the gravitational force, that would make the orbit become elliptical.
  7. Nov 6, 2009 #6


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    They don't have one orbit, just individual orbits which are not perfect circles. The average of the individual orbit is closer to the circle but not a perfect circle either.
  8. Nov 6, 2009 #7
    Thanks for the information, and is gravity responsible for their revolution as it is for the revolution of other celestial bodies?
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