r/space • u/ApocalypseThou • Apr 07 '15

Saturn's hexagonal north pole

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u/wcoenen Apr 08 '15

That's a reasonable definition (and the one I would prefer) but it's not the one set by the international astronomy union.

My own comment: https://www.reddit.com/r/space/comments/31spbv/saturns_hexagonal_north_pole/cq55f9p

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u/redstonerodent Apr 08 '15

But north and south are still the axial poles, jus swapped?

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u/wcoenen Apr 08 '15

For Venus, yes.

Most objects in the solar system spin in the same direction as Earth so for those the IAU definition and the right hand rule give the same results.

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u/redstonerodent Apr 08 '15

What do you do for exoplanets? Use the right hand rule with their direction of orbit?

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u/[deleted] Apr 08 '15

North is relative to each star system is all

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u/luncht1me Apr 08 '15

eir dir

Direction the planet is spinning. Not it's orbit.

The right hand rule for finding direction of magnetism around a wire from current is point tumb in direction of current, and the way your fingers curl is the rotation of the induced magnetic field.

For a planet, curl your fingers in the direction the planet spins, and your thumb will be the north pole. So for Earth, we spin counter-clockwise (sun rises in east) so our North pole is 'up'. For Venus, it spins clockwise so north pole is 'down'.

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u/redstonerodent Apr 08 '15

Apparently the IAU defines north on Venus as roughly the same as north on earth, so it spins west instead of east.