Basic Concepts
In a nutshell: Earth has four main systems—geosphere, hydrosphere, atmosphere, and biosphere—that work together to support life.
## What Makes Up Our Planet?
Earth is made up of four main systems that work together to support life. These systems are:
- **Geosphere**: The solid part of Earth, like rocks, mountains, and soil.
- **Hydrosphere**: All the water on Earth, including oceans, lakes, rivers, and even the water in the air!
- **Atmosphere**: The blanket of gases that surrounds our planet, which we breathe and that protects us from the Sun.
- **Biosphere**: All living things—plants, animals, and people.
## How Do These Systems Work Together?
These systems are always interacting. For example, rain (hydrosphere) falls on the ground (geosphere), helps plants grow (biosphere), and moves through the air (atmosphere).
## Why Are Earth's Systems Important?
Understanding these systems helps us learn how Earth works and how to take care of our planet.
Examples
- A river (hydrosphere) eroding rocks (geosphere) and watering plants (biosphere) under the sky (atmosphere).
- Plants (biosphere) using sunlight and air (atmosphere) to grow in soil (geosphere).
Key terms
- Geosphere
- The solid part of Earth, including rocks, soil, and landforms.
- Hydrosphere
- All the water on Earth.
- Atmosphere
- The layer of gases around Earth.
- Biosphere
- All living organisms on Earth.