Why Do Revolving Bodies Have Elliptical Orbits?

[Shahin.Omar]

Why revolving bodies have their orbits elliptical and not perfectly circular (please correct me if I am wrong)?

 

[A.T.]

Why revolving bodies have their orbits elliptical and not perfectly circular (please correct me if I am wrong)?

Is there anything in nature that is perfectly circular? Perfect circles exist in math only.

 

[Vanadium 50]

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.

 

[Shahin.Omar]

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.

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.

 

[mikelepore]

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.

 

[A.T.]

Saturn's rings are a set of large number of bodies and they together form a perfect circular orbit.

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.

 

[Shahin.Omar]

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.

Thanks for the information, and is gravity responsible for their revolution as it is for the revolution of other celestial bodies?