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Since gravity is three dimensional why planets are rotating only in one plane around sun.

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migrated from skeptics.stackexchange.com Mar 14 '13 at 13:17

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marked as duplicate by Qmechanic Mar 14 '13 at 14:57

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Belongs on Physics.SE. Besides, it's not even true. Pluto is not in plane with other planets. –  vartec Mar 14 '13 at 13:15
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Pluto isn't a planet. I don't make the rules, I only live here. –  daveyfaherty Mar 14 '13 at 13:56
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In one line: Conservation of angular momentum. See: Questions about the Solar System –  becko Mar 14 '13 at 14:40
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@daveyfaherty Thanks for the laugh!! :D –  CodeShane Mar 15 '13 at 1:04
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3 Answers 3

It is believed that the planets formed when a cloud of gas underwent gravitational collapse. Any small angular momentum that the cloud started out with has to be conserved, and since the cloud's moment of inertia becomes smaller, it spins faster. Also, the centrifugal force "throws out" the edges of the cloud and makes it more disc-like.

As vartec said, pluto is an exception:

which has lead to speculation that it was gravitationally captured by our solar system rather than formed with the rest of the planets.

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Any citations for that capture theory? As I understand it, the current general consensus on the origin of Pluto is that it's a proto-Kuiper belt object that got locked into an orbital resonance with Neptune when the latter migrated outward. –  Ilmari Karonen Mar 14 '13 at 16:22
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The planets generally are traveling in a plane. The Sun's axis is tilted about 30 degrees to this plane. Pluto's orbit is roughly 17 degrees off of the Earth's orbit. Eris is 44 degrees. There is a distribution of smaller bodies at all inclinations.

http://en.wikipedia.org/wiki/Invariable_plane

http://en.wikipedia.org/wiki/List_of_notable_asteroids#Retrograde_and_highly_inclined

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This is not really an answer. It does not address why it is the way it is. –  Bernhard Mar 14 '13 at 14:14
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I would probably say it has something to do with the gravity or rather fabric of space if you want. E.g. take a look of the shape of our galaxy:

enter image description here

Do you see the similarity?

How the galaxy resembles our solar system?

It's about the fact that after a while the biggest "rotators" like the Sun or biggest planets win and other "slower rotators" will adjust to their way of rotation.

After than they cannot change their rotation from left to right or stop. Other force like collision of other planet or asteroid etc. can cahnge the direction of rotation.

A lot of things are involved. And one of them is gravity too.

Btw. even strange things are pulsars: http://en.wikipedia.org/wiki/Pulsar

This next few lines are off topic just to take in consideration ;): *To tell you the truth the scientists have troubles to detect some meteorites because they are moving too fast etc. So, be very sceptical to all scientists who claim that nowadays science know how pulsars and galaxy works. And the "hypo-theories" changes all the time. Take e.g. how Big Bang was the coolest thing 15- 20 years ago, now it's overcome with multiverse and other things. Another example is Big Freeze (brrr, slow ;) or her majesty recollapsing Big Crunch - These were the hypothesis popular among most of the scientists not more than 2 years ago. Now it seems that our Universe will pop like a balloon when it will get older. Who is right? Hard to say but... ...keep trying ;)

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there is little scientific explanation in this answer. More than half the words are admittedly off topic... –  Nic Mar 14 '13 at 15:05
    
I don't agree with you. Maybe I was using chatty language but the effect of gravity and rotation is still there ;). Consider this : "It's about the fact that after a while the biggest "rotators" like the Sun or biggest planets win and other "slower rotators" will adjust to their way of rotation." Should I go on and start talking about how the mass warp the fabric of space? I guess not. If the OP wants he can take a look at this youtube.com/watch?v=8bfsedg0tQE and he will understand other stuff too. –  Derfder Mar 14 '13 at 15:13
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'will adjust to their wat of rotation' isn't a particularly good explanation of anything. You don't invoke any scientific rationale or mode of action or compulsion by principle. It is simply not an answer. –  Nic Mar 14 '13 at 15:24
    
...according to... you. I may win and my answer could be chosen as the best, you never know baby ;D –  Derfder Mar 14 '13 at 15:28
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@Derfder: Haha, looks like your answer was chosen as the worst. –  DumpsterDoofus Apr 22 at 21:42
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