Geocentric Science

Earth (as well as the other terrestrial planets) formed as rock and other space debris collided (accreted). The collisions provided a huge amount of energy and heated the planets. Many of the planets were mostly molten in their early stages.

The Earth became layered through a process known as differentiation (the heavier, denser materials sank, and the lighter, less dense materials remained at the surface). The Earth’s layers are visible in the diagram, Inferred Properties of Earth’s Interior. Notice the difference in density between the light continental crust (2.7 g/cm3) and the inner core (13.1 g/cm3).