Earth’s spheres and watery homes

Scientists group the parts of our planet into four systems called spheres. The geosphere holds rocks, minerals, soil, sand and landforms, and hot melted rock deep inside the Earth. The hydrosphere holds all the water: oceans, seas, rivers, groundwater and ice. The atmosphere holds the gases that surround Earth, which we usually call air. The biosphere holds all living things, including people. The spheres interact all the time. Rain from the hydrosphere falls on the geosphere and carries soil downhill. Plants of the biosphere take in carbon dioxide from the atmosphere and let out oxygen. Wind from the atmosphere moves sand in the geosphere. People are part of the biosphere, and their actions can change every other sphere.