Earth's Outer Layers

Earth is made up of systems. The four major systems are the atmosphere, hydrosphere, biosphere, and lithosphere, which contain all the air, water, living things, and land.

The atmosphere is the thin layer of gases, mainly nitrogen, and oxygen, that surrounds our planet.

Next is the hydrosphere, which includes all the water on Earth—from oceans to the tiny droplets in the clouds.

Then there’s the biosphere, which is made up of all the living things on Earth, including plants, animals, and microorganisms.

Finally, we have the lithosphere. This is the solid rock layer of Earth, comprising mountains, valleys, continents, and even the rock beneath the oceans.

These systems do not operate independently but are in constant interaction. For example, when rain from the hydrosphere erodes a mountain in the lithosphere, it shapes the land over time.

Also, plants and animals from the biosphere depend on water from the hydrosphere and gases in the atmosphere to survive.

After they die, their remains decompose in the lithosphere, returning nutrients to the soil.