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Why do all of the planets in our solar system move is (more or less) the same plane? It would seem that the planets should all have very different orbital planes, each at a different angel to each other. The fact that all of their orbits are so closely parallel suggests that a force is pulling and/or maintaining the orbits of the planets in a flat plane. What is that force? A similar force also seems to be working at a galactic level too.

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marked as duplicate by Kyle Kanos, Brandon Enright, Qmechanic Mar 27 '14 at 5:12

This question was marked as an exact duplicate of an existing question.


it is because of the way the solar system formed from a cloud of gas. the molecules of gas (mostly hydrogen) were pulled together by gravity which formed a spinning disk of gas around our sun, thus forming the planets all on the same field.

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The spherical cloud to flat disk is not trivial but your answer doesn't address it. – Brandon Enright Mar 27 '14 at 2:59

It's because of Conservation of Angular Momentum.

When all these systems are in the process of creation, all motions not existing in the same horizontal plane cancel each other out which confines them into that plane. The system continues to exist that way due to conservation of Angular Momentum.

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