Question

How does gravitational energy turn into thermal energy and what are its impacts on the atmospheres of giant planets?

1) It is converted through nuclear fusion reactions in the core of the planet.
2) It is converted through friction and collisions between gas molecules in the atmosphere.
3) It is converted through the release of heat from the planet's interior.
4) It is converted through the absorption of sunlight by the planet's atmosphere.

Answer 1

Gravitational energy is converted into thermal energy in giant planets through gravitational contraction, which includes primordial heat retention from formation and additional heat from ongoing slight contraction, raising the temperatures in their interiors and atmospheres.

Step-by-step explanation:

Gravitational energy is converted into thermal energy mainly through the process of gravitational contraction. Regarding the impacts on the atmospheres of giant planets, the conversion of gravitational energy can occur by the following mechanisms:

• Primordial heat retained from the planet's formation when the collapse of surrounding material onto the planet's core converted gravitational potential energy into thermal energy.
• Additional heating by ongoing contraction of the planet, where even a slight shrinking can produce significant heat due to the massive size of giant planets such as Jupiter.
• Gravitational contraction described by Kelvin and Helmholtz, where the energy of inward-falling material due to the planet's gravity is converted into heat.

The above mechanisms raise the temperatures in the interiors and atmospheres of giant planets above what would be expected from just the heating effect of the Sun alone.