# Planetary orbits?

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the Solar system in specific.

Ide like to know whether the planets orbit on a plane of concentric circles as depicted in books. OR, do some go over and under?

we have the sun in the center and a planet going around it, that can be shown in 2D. but might another planet be moving up and over the inner one and the sun, requiring a 3d representation.

I realise this cant be shown on the page of a book very easily, but I find it hard to imagine a reason Why all the planets would be on the same plane in concentric orbitals.

Ive scoured the net for an accurate illustration of what our orbits are REALLY like, and come away empty handed.

any one know for sure or have a good link I can take a look at?

Thnx

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"I realise this cant be shown on the page of a book very easily, but I find it hard to imagine a reason Why all the planets would be on the same plane in concentric orbitals."

I don't know a link, but a possible reason is this (I'm not qualified to answer this in any way, yet I do, silly me):

Solar system long time ago: A cloud-like shape of... stuff. Inner parts start to become more dense. Due to spinning of the cloud, resulting from gravity, the cloud becomes more and more flat; a disc like shape. That's the reason planets are quite right on the same level.

I'm not quite sure if the star-forming makes the cloud spin, but that's what I've heard. If it's wrong, blame someone else than me.

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The ecliptic is the idealized plane for the earth's orbit, and the other planets lie close to it, but not directly on it. That's why there are not eclipses and occultations every time planetary bodies line up radially.

We just had a lunar eclipse last full moon, but we don't get one every full moon (inclination is about 5 degrees). We had a transit of Venus in June, and will have another in 2012, but then not for more than 100 years (and didn't have one at all in the 1900's), becaus Venus's orbit is inclined with respect to the ecliptic by 3.39 degrees.

Here is a table of planetary data. You can see that, except for Mercury and Pluto, the planets are all within 3.39 degrees.

And the orbits are elliptical.

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Excellent resource, thank you

an animated pictorial would be interesting to see (no I dont need one now) just for the Visual appreciation of it

so is it the spinning gas cloud idea that causes this?

it would certainly seem to make sense!

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so is it the spinning gas cloud idea that causes this?

it would certainly seem to make sense!

Basically. Angular momentum is conserved, so what spinning you have defines an axis for the whole system. Any orbits that are not primarily on the ecliptic, or are very eccentric, will intersect, so you get collisions of any objects that have coelesced that have those orbits. What survives are objects near the ecliptic with fairly round orbits.

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I am studying elliptical orbits in physics right now, one thing to note is Pluto is way off the elliptical (then again Pluto is arguably even a planet). But if you notice most galaxies form an elliptical movement also, unless otherwise interrupted by outside forces. I looked all over for some good links for you but, I did not find any. There is a movie I would reccomend called Cosmos by Carl Sagan,you can find it in most libraries here in the US so you should have it in England too, it gives some nice 3-d interpretations of how galaxies and solar systems form. It should give you the mental appreciation you were looking for.

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• 3 weeks later...

If I may ask a question that seems to follow from the first.

As I understand the process, the steps are like this;

1. Cloud of gases and particles.

2. Forms an accretion disc.

3. Planets form out of the disc.

I assume the original disc is something like the Rings of Saturn. (God what a sight, a "Ringed Star", it boggles the mind.)

Now as it forms the planets. How? It's a bit hard to describe my question.

As Earth formed, where did it collect the matter from? Did the gradually increasing Earth mass speed up the mess in the Earth/Venus area and slow down the mass in the Earth/Mars area?

Or did we get most of the mass from between the orbits of Earth and Mars? Venus would therefore get most of it's mass from the area between the Earth/Venus orbits.

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Or did we get most of the mass from between the orbits of Earth and Mars? Venus would therefore get most of it's mass from the area between the Earth/Venus orbits.

I understand that this is the correct explanation. There are several groups doing research with finite element analysis to simulate the formation of planets. I've waded my way through a few of their research papers in the past and don't recall that the issue is specifically addressed, but the implication is as you say.

Ooops I've left in the wrong explanation. Earth would have gots its mass from both closer in and further out, though intuition would suggest a larger portion from further out.

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I think this can be possible:

the sun has a rotation motion and at its equator the tangential speed is more high.

If a superficial explosion at equator occurs then the mass has more probability to go out of the sun forming the planets with all its 2D orbits

near the solar equatorial plane.

Can it be possible?........

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I believe that's how our planets formed initially but what I don't understand is why the sun was in orbit without purpose unless there was some kind of supreme forward thinking like the whole solar-sysyem was pre-planned if that was the case then maybe relgion would be an explanatory factor; anyone with practical theories?..... us.2u

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the sun doesnt orbit anything in our locality so Ive no idea what made you think that?

the sun (our sun) and countless other stars like it are in orbit around the center of our Galaxy sure, but thats all

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us.2 ,

what is the purpose of nature ?

Religion can't explain it but can only give reason to why humans should believe nature is the force of Gods 'will', a human invention of thought.

..

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Thanks Ophiolite. Clearer now.

In every other explanation I've seen, no-one seems to really mention which planet got what from where. I would have thought that that would be a vital part of planetary formation dynamics.

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Ide suspect that hardly any actualy started off as "planets" (pre-made chunks) but rather a collection of random collisions of smaller particles that eventualy create a total mass with a strong enough gravitational feild to form itself into a sphere type shape.

Some (such as ours) will be "lucky enough" to even capture gasses or an Atmosphere within its pull.

the Asteroid belt (Van Halen or Allan, LOL) Could potentialy make another Planet (if the circumstances were right), its thought that it could originaly have been a planet once?

so space dust and rocks accumulate into bigger groups and gravity just does the rest

probably not the EXACT answer you were looking for, its the best to my understanding anyway

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Orbital inclinations from extrasolar.org

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the Asteroid belt (Van Halen or Allan, LOL) Could potentialy make another Planet (if the circumstances were right), its thought that it could originaly have been a planet once?

I'm not sure if that is a question or a comment but since you have a question mark I will assume that is not a typo

From my understanding it is thought by some that the asteroid belt was in fact a planet at one time that has been broken apart by unknown causes (some theories point to the gravitational tug of war between Jupiter and the Sun) This is thought because if you measure the distance between the planets there is a reletive pattern which suggests a planet should have formed between Mars and Jupiter, the search for this planet is what actually was the discovery of the asteroid belt.

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Orbital inclinations from extrasolar.org

Huh, I didn't know Venus was so far off, I thought it was pretty stable. But then it does have a retrograde rotation, so thats pretty wierd, I guess that kinda shows that its orbit isn't all that it should be.

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'']Huh, I didn't know Venus was so far off, I thought it was pretty stable. But then it does have a retrograde rotation, so thats pretty wierd, I guess that kinda shows that its orbit isn't all that it should be.

I guess you didn't read post #3. Venus is inclined less than the moon is.

I don't think the inclination angle has anything to do with stability - it's not like the angle is changing.

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• 2 months later...
'']Huh, I didn't know Venus was so far off, I thought it was pretty stable. But then it does have a retrograde rotation, so thats pretty wierd, I guess that kinda shows that its orbit isn't all that it should be.

It looks like Earth is used as the baseline. If Jupiter was used Venus would be closer than what is shown.

Question: How does the Sun's rotation line up?

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It looks like Earth is used as the baseline. If Jupiter was used Venus would be closer than what is shown.

Question: How does the Sun's rotation line up?

Closer than what? It would still be inclined the same with respect to the earth. The relative inclines would be the same no matter which baseline was used.

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Closer than what? It would still be inclined the same with respect to the earth. The relative inclines would be the same no matter which baseline was used.

Closer as in :

Venus does not look to be much further off the "main" plane of the planets (which I am assuming would be close to Jupiter's plane of orbit) than Earth does, just that it's on the "other side". But it looks like they used Earth's plane of orbit as the baseline. so Venus looks further "off" (which I'm guessing brought about the post/remark about Venus.

This made me wonder what plane of rotation the sun itself had.

Another thought is: "how about the asteroid belt"?

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This link takes you to a page with a nice 3D virtual tour of the solar system. You do have to down load the viscape svr plug in to run it and it requires a restart but then you can see the orbtal planes and if you click on a planet you can see the orbits of moons too, shame it takes the messing but I liked it. It may ask to use your own 3D graphics chip which worked ok for me. Hope this elps. P.S. if you get the downloading textures for the moons it seems to freeze but it just takes a bit to load up. P.PPP.P.S.S.SS A WARNING TO EPILEPTICS.Left click on space slows action to limits of program right click speedS it up to visual cortex in a blender type speeds.

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Closer as in :

Venus does not look to be much further off the "main" plane of the planets (which I am assuming would be close to Jupiter's plane of orbit) than Earth does' date=' just that it's on the "other side". But it looks like they used Earth's plane of orbit as the baseline. so Venus looks further "off" (which I'm guessing brought about the post/remark about Venus.

[/quote']

Depends on how you look at it - you could take the center of mass line, and distribute the plantes on either side. But remember, the orbits go all the way around, so you have to project those lines through the origin. What you've done is rotate the whole thing a few degrees - it's still a bowtie shape, and the angle between extrema doesn't change.

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This made me wonder what plane of rotation the sun itself had.

Another thought is: "how about the asteroid belt"?

The suns rotation axis is tilted 7.25 degrees. Asteroids have a range of inclinations.

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Depends on how you look at it - you could take the center of mass line, and distribute the plantes on either side. But remember, the orbits go all the way around, so you have to project those lines through the origin. What you've done is rotate the whole thing a few degrees - it's still a bowtie shape, and the angle between extrema doesn't change.

Thank-you. You caught me thinking a little too "2-D".

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