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Old 07-08-2010, 05:11 PM
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renormalised (Carl)
No More Infinities

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Join Date: Apr 2008
Location: Townsville
Posts: 9,698
Yes, to all of them

The orbits of all planetary bodies change shape all the time, over long periods of time. The Moon is moving further away by about 2-3cm a year, due to tidal forces between it and the Earth transferring our rotational angular momentum into its orbital motion. Eventually, our day and its day will be the same length...about 30-36 days long. Not only that, but the planet's orbits are changing their shape all the time, due to the various gravitational forces being exerted upon them. Changes in ellipticity, orbital tilt, points of perihelion and aphelion etc, all occur to the planets over time. Some orbits become more elliptical, others round out. The moons of the other planets all follow the general trend of changing orbits over time...some move in or out, others become more highly inclined and others less so. All due to the gravitational forces being exerted upon them and how these forces between the bodies balances out.
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