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How does hydrogen behave deep inside Saturn?
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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.
Deep inside Saturn, hydrogen undergoes significant changes due to extreme pressure and temperature:
- Liquid State: At depths greater than 1,000 km (600 miles) below the clouds, where pressures exceed one kilobar, hydrogen exists as a liquid rather than a gas.1
- Metallic State: At a depth roughly halfway to the centerāwhere pressures reach about two megabars and temperatures hit 6,000 Kāthe fluid molecular hydrogen undergoes a phase transition into a metallic state. This state resembles a molten alkali metal, such as lithium.1
- Electrical Conductivity: This fluid metallic hydrogen is electrically conductive. Its circulation, driven by heat flow and the settling of denser materials, generates Saturn's magnetic field through dynamo theory.1
- Helium Precipitation: Within the metallic hydrogen layer, helium may precipitate out of solution, forming dense droplets that "rain" toward the planet's interior. This process converts potential energy into heat, which helps explain Saturn's internal energy output.1