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Author Topic: Do all planets rotate like Earth?  (Read 19935 times)

Janet

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Do all planets rotate like Earth?
« on: 19/10/2008 12:19:01 »
Janet asked the Naked Scientists:

I wanted to know if all planets rotate as well as revolve. If not, which
planets?

What do you think?

dentstudent

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Do all planets rotate like Earth?
« Reply #1 on: 19/10/2008 12:40:59 »
There are some differences in the rotational direction in the planets - all but 2 rotate anti-clockwise like the earth. Venus has its axis of rotation (ie its poles) in its side, and so is effectively "rolling" around in its orbit rather than spinning. Uranus has completely flipped and so has its axis in a similar orientation to earth, but is spinning the other way (ie clockwise). I think (but someone else should qualify) that mercury is close to being tidally locked to the sun which means that there is always one side of Mercury that is facing the sun, or at least a very long day length if it is not fully locked.

http://en.wikipedia.org/wiki/Tidal_locking
« Last Edit: 19/10/2008 12:44:44 by dentstudent »

Soul Surfer

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Do all planets rotate like Earth?
« Reply #2 on: 19/10/2008 12:42:24 »
in general all astronomical bodies rotate but the rotation rate can vary quite a lot.  Jupiter the largest planet rotates very quickly only taking about 10 hours to rotate.  This is so fast that it is notcably flattened.  On the other hand Venus takes longer to rotate than it does to revolve around the sun

chris

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Do all planets rotate like Earth?
« Reply #3 on: 20/10/2008 06:53:58 »
Uranus rotates on its "side"; originally scientists thought this was the consequence of some kind of cosmic collision. More recent models of the gestation of the solar system, however, suggest that it might instead be a "resonance" effect resulting from the gravitational interactions of the nascent (forming) planets as they jostled for position.

dentstudent

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Do all planets rotate like Earth?
« Reply #4 on: 20/10/2008 08:11:50 »
My mistake about Uranus - sure I heard it from an astronomy podcast. Anyway, here is a link that shows the angle of the axis of Uranus...

http://www.planetary.org/blog/article/00000553/

 

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