Earth's Systems

The hydrosphere consists of all the water on, over, and under Earth's surface. More than 70 percent of Earth's surface is covered by liquid water. Water can also be found frozen in ice caps and glaciers, and in the air as water vapor and clouds. Discover more in Hydrosphere, a title in the Earth's Systems series.

The lithosphere is made up of Earth's rocks and minerals. Only the outer part of the lithosphere is visible. This is the thin crust that covers the whole planet. Discover more in Lithosphere, a title in the Earth's Systems series.

The atmosphere is made up of all the air above and below Earth's surface. It has five main layers. Each layer contains particles of gas. Discover more in Atmosphere, a title in the Earth's Systems series.

The biosphere includes all living things, large and small. Life in the biosphere is a constant competition. Organisms compete for the resources that keep them alive, including air, water, and land. Discover more in Biosphere, a title in the Earth's Systems series.