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Q & A: why do planets orbit almost in a plane?

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Q:
why is it that the planets orbit "around" the sun and no over it? do magnetic poles have anything to do with a planet or stars bending of space
- chad (age 27)
england
A:
With any one planet you could say that it orbited around the sun regardless of how the orbit was oriented. I think what you're asking is why all the planets have orbits that are nearly in the same plane. The sun itself also spins around an axis that is nearly at right angles to the same plane. As I understand it, as the solar system started to condense, it had some net angular momentum, just by the usual accidents of motion in a lumpy environment. That angular momentum was conserved as the material started to lump together.  The planets were left behind orbiting around that angular momentum axis, as nature's way of conserving angular momentum.

Some similar process is quite typical in star formation. Many stars have orbiting planets. Some stars form pairs, orbiting each other.

As for your other question, the "bending of space" is gravity, caused by any form of energy or momentum. Magnetism plays a negligible role in it since it accounts for a negligible fraction of the total energy of the solar system. It's interesting that very many of the people who write us want to know about the connection between magnetism and gravity, although there's almost none.

Mike W.

(published on 03/27/2011)

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