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Why is earth's path is elliptical?why not circular?

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- Thread starter kamalee
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- #1

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Why is earth's path is elliptical?why not circular?

- #2

Garth

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Welcome to these Forums **kamalee**!

A circular orbit is a special case of the general elliptical orbit in which the eccentricity is exactly zero.

As nothing is exact in the real world the Earth's orbital eccentricity is near zero but not exactly zero.

In fact e = 0.016722, therefore its orbit is elliptical, just as Kepler's laws says it should be....

Garth

Why should it be circular?kamalee said:Why is earth's path is elliptical?why not circular?

A circular orbit is a special case of the general elliptical orbit in which the eccentricity is exactly zero.

As nothing is exact in the real world the Earth's orbital eccentricity is near zero but not exactly zero.

In fact e = 0.016722, therefore its orbit is elliptical, just as Kepler's laws says it should be....

Garth

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Do any truly circular orbits exist (Eccentricity = 0)?

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mathman

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Do any truly circular orbits exist (Eccentricity = 0)?

None of the planets have 0 eccentricity. I suspect most of the artificial earth satellites have a very small eccentricity, so it is possible one or more might be zero. However it would be hard to maintain since the moon would exert some perturbing force.

- #5

russ_watters

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Well, the answer can be seen in probability: Since, as Garth said, 0 is just one possible eccentricity, the odds of that happening are infinitessimaly small. So no, it would really be impossible to have an exactly zero eccentricity.Do any truly circular orbits exist (Eccentricity = 0)?

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Thanks Guys!!!!

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The Earth revolves around a moving object. Hence an elliptical orbit.

No Math required on this one.

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ideasrule

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The Earth revolves around a moving object. Hence an elliptical orbit.

No Math required on this one.

As someone mentioned in the other thread, that's incorrect. The Sun doesn't care whether it's in motion or not; there's no way to tell anyhow because there is no privileged reference frame.

When talking about the shapes of orbits, it's usually done from the reference frame of the barycenter. Obviously, an orbit's shape is going to be different if you watch it from, say, the reference frame of a cosmic ray.

- #9

DaveC426913

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Visualedtech, stick to what you know. Your knowledge of orbital mechanics is ... limited.

The Earth revolves around a moving object. Hence an elliptical orbit.

No Math required on this one.

Also, this post is two years old.

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