Page 38 - Curriculum Visions Dynamic Book

 A false-colour picture of Saturn’s northern hemisphere. There are several weather patterns visible. Two spots are flowing westward at about 15 metres per second. The third, most westerly, spot has a cloud system that is part of this westward flow, although the spot itself is flowing east at about 30 metres per second. The ribbonlike feature to the north marks a high-speed flow
of air where wind speeds approach 150 metres per second.
The core of Saturn is made of 50% hydrogen. But at the huge pressures existing in the centre of the planet, the hydrogen changes from a liquid and becomes a liquid metal (to imagine this, think of the silvery metal mercury). At the very core there may well be a mixture of rock and ice of up to 20 times the mass of the Earth.
The churning over of the liquid metallic hydrogen near the core is responsible for the magnetic field. Saturn’s magnetic field is similar to that of the Earth, resembling a giant bar magnet. The magnetic field lines up almost exactly with the geographical north and south poles and is not offset, as on the Earth.
Like Jupiter, Saturn radiates more heat to space than it receives from the Sun, and so it must have a hot core.
The fact that Saturn has no solid surface makes it difficult to say how big the planet is. The diametre of the planet is usually taken to be about 121,000 km.
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