Based on the protoplanet hypothesis, how did the earth end up being layered the way it is?

Question

Claire Anctil · Accepted Answer

The original accretion created a uniform mixture of rock and iron. And then, as is often the case when you have a big thing, gravity took over ... see below.

Originally, the pieces that came together to make up the Earth were bits of rock and iron that were assembled randomly. The planet was primarily a uniform mixture of rock and iron. But then the accumulated heat from gravitational compression and the still warm nebula caused these materials to melt. And when they did that they could flow in response to gravity. The iron-rich material, being denser, sank beneath the less dense rocky stuff that henceforth would be floating on top, a process called differentiation. A secondary differentiation has also occurred within the rock, bringing less dense minerals into the crust on top so that the crust and mantle have different compositions. Differentiation has occurred in all terrestrial planets and even dwarf planets and some larger moons. Our own moon, for instance, is almost all rock but even this has a small iron core. There are also bodies where ice is differentiated from rock like Pluto, or even three layers consisting of an icy outer layer then the rock and an iron core. Jupiter's moons Europa and Ganymede seem to have that three layer structure, with some of the ice melted to a watery ocean beneath the surface.

Olivia Aldridge · Answer

undefined According to the protoplanet hypothesis, in the early phases of solar system formation, smaller planetesimals collided and accreted to form larger bodies known as protoplanets. Radiation decay and gravitational compression heated these protoplanets, causing differentiation: lighter materials rose to the surface, forming the mantle and crust, while heavier materials sank towards the center, forming the core. This process resulted in the layering of the Earth with a thin outer crust, a rocky mantle, and a dense metallic core.

Owen Atkinson · Answer

undefined Based on the protoplanet hypothesis, the Earth ended up being layered the way it is through a process called differentiation. This occurred during the early stages of the Earth's formation when it was still in a molten state. As the Earth accreted material from the protoplanetary disk, gravitational forces caused heavier elements such as iron and nickel to sink towards the center, forming the dense metallic core. Lighter materials, such as silicates and other minerals, remained closer to the surface, forming the Earth's mantle and crust. This process of differentiation resulted in the distinct layering observed in the Earth's composition today.