I thoroughly enjoyed our class discussion about the origins of the hot, molten core of Earth. It is cool to think about how the modern heat in our planet’s interior is a result of thousands of years of activity and energy transfer.
As we learned in class, a planet derives internal heat from three sources during its lifetime. Accretion is one form of heat collection and happens in early formation. Collisions of planetesimals converts kinetic energy to thermal energy which is stored in the interior. Next, the process of differentiation adds heat to the planet due to more dense materials settling towards the gravitational center of the body. As mass falls, it converts potential energy to thermal energy therefore heating the core. Finally, heat from radioactive decay occurs throughout a planet’s lifetime. Overtime, the nuclei of elements lose subatomic particles which creates energy generating collisions.
Accretion and differentiation happen very early in a planet’s life while radioactive decay can occur consistently. It was interesting to me to learn that most of our planet’s heat is due to processes so long ago. It illustrates the sheer magnitude of the thermal energy in our planet’s core.