What are the shapes of orbits that exist in our solar system

[LukeyD]

Can anyone help me please?

Are they all elliptic or just some?

I need to know for planets, comets, moons and satellites

All help greatly appreciated.

[Algr]

Any two-body orbit is going to be an ellipse. A third body might disrupt the elliptic orbit, but then it would just turn into a different ellipse.

[D H]

Any two-body orbit is going to be an ellipse. A third body might disrupt the elliptic orbit, but then it would just turn into a different ellipse.
Adding a third body to the mix in general makes all of the bodies follow non-elliptical paths.

[phyzguy]

Any two-body orbit is going to be an ellipse. A third body might disrupt the elliptic orbit, but then it would just turn into a different ellipse.

I don't think this is quite right. A two body orbit must be one of the conic sections (ellipse, with circle as the limiting case, or hyperbola, with parabola as the limiting case). It's true that any closed orbit is an ellipse, but comets can come from outside the solar system and follow hyperbolic orbits. I

[Algr]

I see. I was thinking of "orbit" as something that had to be stable. The Earth orbits the Sun in an ellipse, the Moon orbits the Earth in an elipse, but if the Sun were to have a significant effect on the moon, the system would destabilize until one of the bodies no longer had a significant effect on one of the others.

[D H]

A better term is closed orbit; pyshzguy is generalizing the concept of orbit to that of any path followed as a result of gravitation. I don't want to get into the semantics argument of which is right: hyperbolic trajectory versus hyperbolic orbit. Just use the term closed orbit and everyone will know you are not talking about objects on an escape trajectory.

That said, the Earth does not orbit the Sun in an ellipse. None of the planets do. The orbits of planets are instead some nameless shape that are very close to being ellipses.

[johnt447]

There is no reason why a orbit can't be a perfect circle. For this to happen the orbiting body has to be travelling at the right speed so for the right speed to be attained by a natural occurring body like a planet is very unlikely

[D H]

There is no reason why a orbit can't be a perfect circle. For this to happen the orbiting body has to be travelling at the right speed so for the right speed to be attained by a natural occurring body like a planet is very unlikely
In the two body problem this is a space of measure zero. In other words, circular orbits while theoretically possible in the two body problem they will never occur in practice.

In our solar system, never, period.

[Tyrannical]

What are the shapes of orbits that exist in our solar system

Extremely complicated :biggrin:

Every object in the solar system (and some things even outside the solar system) influences the orbit of every other object. Normally these object have to be big, but when you consider the nine or so planets, and the moons orbiting each planet this has to be taken into account when computing orbital trajectories.

[Radrook]

Generally speaking, our solar systems orbits are are closed eliptical orbits as opposed to parabolic or hyperbolic ones in which an object flies by and never returns.



List of types of orbits
http://en.wikipedia.org/wiki/List_of_orbits