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Why is Saturn flattened at its poles?
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Saturn
Saturn and its spectacular rings, in a natural-color composite of 126 images taken by the Cassini spacecraft on October 6, 2004. The view is directed toward Saturn's southern hemisphere, which is tipped toward the Sun. Shadows cast by the rings are visible against the bluish northern hemisphere, while the planet's shadow is projected on the rings to the left.
Saturn appears flattened at its poles because it is an oblate spheroid, a shape caused by its rapid rotation.12
With a rotation period of approximately 10 hours and 33 minutes, the planet's rotational acceleration creates a significant outward force at the equator. This force effectively cancels out a larger portion of the planet's gravity at the equator than at the poles, causing the equatorial region to bulge outward.12
As a result, Saturnās equatorial diameter is significantly larger than its polar diameterāa difference of about 10 percentāmaking it the most oblate planet in the solar system.12