Question

Briefly describe the interior structure of Jupiter and explain why it is layered in this way. How do the interiors of the other jovian planets compare to that of Jupiter?

Answer 1

There is no surface to the giant planets, only a gradual change from the atmosphere, as shown in this drawing.

The gases which Jupiter is mostly made of change to liquid inside Jupiter, but the change is very gradual. Therefore the giant planets do not have strict layers, as the earth-like planets do.

The liquid sections of Jupiter form by far the largest portions of the planet, and penetrate very deep into the planet. The first liquid layer inside Jupiter, immediately under the atmosphere, is the liquid hydrogen layer. Under the liquid hydrogen layer is a liquid metallic hydrogen layer.

The jovian planets get their heat from the Sun and from their interiors. Jupiter creates a lot of internal heat and releases this heat by emitting thermal radiation. In fact, Jupiter creates so much internal heat that it emits almost twice as much energy as it receives from the Sun. The only reasonable explanation is that Jupiter is still slowly contracting, almost as though it has not quite finished forming.

Saturn and Neptune also appear to be emitting more energy than they receive from the Sun. While we are certain Saturn is not still contracting, it seems clear that Neptune is still contracting. Uranus is the only jovian planet not emitting excess internal energy.