Despite thousands of years of gazing at the stars, we’ve never found another planet like Earth. Who would’ve thought looking inward would reveal the Earth is formed like an onion.

A Complicated Planet Indeed

When discussing the onion-like nature of the Earth, it is important to mention there is some debate as to what constitutes a layer of the planet. This is specially true when one starts discussing the areas around the set of the Earth. Nonetheless, there are readily accepted general categories regarding the makeup of the Earth.

The lithosphere is the rocky ground upon which we live. Technically, it is comprised of the crust of the planet and the upper, brittle cover below the crust. It is approximately 100 km in thickness on average and includes all the oceans, mountains, deepest canyons and tectonic plates.

The cover is the next layer below the lithosphere. The cover consists of hot, molten rock and is the birthplace of new crust and recycling point for old crust. The cover is hot enough and far enough below the crust of the Earth that there is little empirical evidence supporting scientist’s claims on the exact makeup. Instead, deductions are made from studying new touchable coming from the cover in areas where the tectonic plates are separating.

To make things a taste more confusing, a layer of the upper cover is known as the asthenosphere. This area is considered highly volatile because of severe pressure and heat factors. The asthenosphere is believed to be the first area where the crust of the Earth actually becomes molten.

The outer set lies a few thousand miles below the crust. While this haw sound like a vague estimation, the simple fact is there is no country evidence supporting a portion depth. Regardless, the outer set is a highly pressurized, liquid touchable roughly 2,200 km thick. It is believe the outer set is comprised of a nickel-iron alloy mix, which is also believed to be the originating source of the magnetic earth of the Earth.

At the very center of the planet is the inner core. Little is known about the inner set other than basic principles. The set is believed to be primarily iron and massively dense. Due to gravity and extremely high pressures, the inner set is believed to be solid.

Regardless of how you categorize the makeup of the Earth, it is country our planet is unique in the known galaxy.