Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: neilep on 20/12/2007 16:26:36
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Dear Planetoid Orbitologists,
As ewe know the moon is gradually extending it's distance from Earth by a small amount each year !!
Does this also happen to our orbit around the Sun ?....in fact...does it happen to all the planets ?...and what about the moons around those planets ?
Hugging ewe all in anticipation of answers that will make my mouth smile !! [;D]
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i would assume that as it is happening to all other planets that it wud happen to Earth to wat makes it diffrent?
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Yes i believe all the planets are slowly moving away fom the sun due to tidal action
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Isn't it due to the generally expanding universe?
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Hasn't the Moon been affected my the Apollo missions? The mass has been changed slightly, due to all the stuff the Americans left behind, so this would affect the orbit slightly.
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Isn't it due to the generally expanding universe?
No because the expansion force is too weak. it only shows itself in deep space where the galaxies are so far apart that they cant interact with each other gravitationally
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This is a very difficult question. The main planetary orbits are dominated by Jupiter and their positions are in a sort of metastable state so they are all speeding up a bit and slowing down a bit as energy passes between them. hopefully things will stay that way for a very long time unless a passing star gets too near and disrupts things a bit when anything could happen.
Minor planets and comets are probably too small to cause any major orbit problems for the min planets whatever they do. Interaction with the solar wind could cause a minuscule loss of energy form the planets' orbits and magnetic field interactions could give energy from the rotating sun to the planets but these too effects are probably too small to be significant.
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Just as an aside, when did Saturn and Jupiter get to their closest point. I would think that the rings would get affected by Jupiter...wouldn't they?
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The main planetary orbits are dominated by Jupiter and their positions are in a sort of metastable state so they are all speeding up a bit and slowing down a bit as energy passes between them.
Does this mean that Jupiter has an impact on the Earth's weather/climate?
I had always assumed some slight impact must be there, but you seem to be indicating it should be even a measurable (even if still small) influence.
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I believe that Jupiter has an indirect influence on Earths climate in as much that its orbit around the Sun may well be the source of the 11 year sunspot cycle which has a small influence on our climate
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The earth does have regular orbit changes that do affect the climate long term.
look up The Milankovitch theory.
The sunspot cycle is really an approximately 22 year cycle because the magnetic polarities of the sunspots change. It is almost certainly an electromagnetic process and unlikely to be due to Jupiter's orbit.
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It is my understanding that the expansion is not due to a 'force'. It just is space expanding. If it were a force, then those galaxies, way out there, would be subject to F=ma and general relativity constraints. If the force is so weak, then far away galaxies would be limited on their velocity.
The planets are in stable orbits with respect to one another. So if Earth's orbit moved slightly with respect to the other planets, gravity would nudge Earth into a stable orbit. Likewise for the other planets. They would all 'dance' around until stability was achieved.
If the planetary orbits are indeed moving out, then it must be imperceptibly slowly. One of the astronomers out there could probably estimate the rate of orbit expansions.