# Questions tagged [eccentricity]

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### Eccentricity of TLE orbit from velocity and radius in TEME

I was reading this question: Calculation of Eccentricity of orbit from velocity and radius and tried to use the proposed equation to reconstruct the ecco field of TLE by it's R,V vectors. The formula ...
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### Which one of the gas and ice giants has the least varying orbital characteristics? [closed]

Which one of the gas and ice giants of our solar system has the least varying orbital characteristics (obliquity, eccentricity etc.)?
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### On Mars, why are the seasons "strongly amplified" in the southern hemisphere and masked in the northern hemisphere?

In the Darian calendar entry on Wikipedia we read (emphasis mine): The Martian year is treated as beginning near the equinox marking spring in the northern hemisphere of the planet. Mars currently ...
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### Neptune's eccentricity stability

Will Neptune's orbital eccentricity remain lower than earth's forever? It currently is at around 0.008, compared to Earth's 0.0167.
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### Lagrange points for bodies in elliptical orbits?

Lagrange points are points of relative stability near the orbit of another, more massive body. Most of the examples of such points regard orbits with relatively low eccentricity. However, after ...
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### Path of sun in the sky on a planet with no axial tilt

Some sources online (e.g. this, see section "Effect of Earth’s Eccentricity") claim that if the earth's axis was not tilted, then the analemma would have the shape of an ellipse/oval. I ...
298 views

### Best way to procedurally generate an orbit given mass and eccentricity

As stated here, I've badly expressed my problem and have made what we call a XY problem (the question was well answered nonetheless) so I restate the question. Sorry for the inconvenience I have a 2D ...
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### Is the 'spin' of Earth and the 'spin' of Mars a significant contribution to their angular momentum?

Is the 'spin' of Earth and the 'spin' of Mars taken into account as a contribution to the conservation of angular momentum? (and a contribution to the increasing/decreasing eccentricity?) Or - is the ...
3k views

### What is the difference between the two terms named "Eccentricity" and "Ellipticity"?

I don't get the difference between the two terms named "Eccentricity" and "Ellipticity", especially, in astronomy. I understand eccentricity as a measure of the curvature of a ...
23 views

### Relation between inner and outer eccentricities in a hierarchical triple star system

According to Table 3 of Sterzik & Tokovinin (2002), the inner eccentricity of a triple star system (i.e. the eccentricity of the inner binary) is, most of the times (70%), larger than the outer ...
602 views

### Cannot identify mistake in calculating orbital eccentricity vector; magnitude equals one instead of zero (with python code)

I have a gravitational nbody simulation, for which I would like to determine various orbital parameters. For each body, I have 3-D vectors (x,y,z -space) for position, velocity, and acceleration. I am ...
139 views

### Does gravitational radiation change the eccentricity of binary orbits?

Do the eccentricity of a binary orbit change with change in the semimajor axis due to loss of orbital angular momentum by gravitational radiation?
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### What kind of effects can maintain Uranus' rings' eccentricities?

The recent paper Thermal Emission from the Uranian Ring System has been in the news recently. The introduction mentions: The ε ring, the brightest and most massive of the narrow rings, was shown to ...
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### How close to circular is the Earth's equator

Earth's orbit is about 99% circular. How circular is Earth around the equator? I know it bulges around the equator and is a spheroid. I also know it is not smooth and has oceans and mountains and all ...
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### Calculation of Eccentricity of orbit from velocity and radius

For a school project I am making a gravitational computer model. As I want to Milankovitch cycles, I need to calculate the eccentricity of an orbit after the model has completed its simulation. I ...
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612 views

### Why has the orbit of Venus such a low eccentricity?

The eccentricity of Venus is almost 14 times smaller than that of Mars, and 2.5 times smaller than that of Earth, and 30 times smaller than that of Mercury. Is it just a pure fluke? Or is there some “...
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