Planetary magnetic fields are produced by the motions of electrically conducting liquids deep within planet interiors. In Jupiter and Saturn, magnetic fields are generated in deeply buried layers of metallic hydrogen. In Uranus and Neptune, magnetic fields arise in salt brine oceans. The geometry of the magnetic fields of the giant planets can be schematically illustrated as if they came from bar magnets in the interiors of the planets (Figure 10.18). All of the giant planets have magnetic fields that are much stronger than Earth’s.