In this region, the pressure in the atmosphere is comparable to that on Earth. Much in the way your ears feel pressure when you dive to the depths of a pool due to the weight of the water above you, the pressure inside Jupiter grows with depth in the atmosphere. This layer gradually changes from gas to liquid as the pressure increases. Unknown on Earth, liquid metallic hydrogen forms under the extreme pressures that exist on Jupiter. At this depth, the pressure is more than three million times what it is at the surface of the Earth.
Hydrogen molecules are so tightly packed that they break up and become electrically conductive.
Scientists believe it is this electrically conductive liquid that causes Jupiter's intense magnetic field. If there is a solid surface, one could not stand on it without being crushed by the incredible weight of the atmosphere above. One of the by-products of Jupiter's ocean of liquid metallic hydrogen is a magnetic field stronger than that of any other planet. A compass used at Jupiter would point south rather than north as it would on Earth, meaning Jupiter's magnetic field is inverted compared to Earth. The area surrounding a planet that is dominated by the planet's magnetic field is called a magnetosphere.