Lesson 9: Air and the Atmosphere
Earth's atmosphere is a layer of gases held close by gravity. This lesson connects air with the geosphere, hydrosphere, and biosphere and the ways these parts of Earth interact.
Key Ideas
- Air is matter. It takes up space and has mass.
- The atmosphere is the layer of gases around Earth. Gravity helps keep it near our planet.
- The Moon has far too little gas around it for us to breathe or have weather like Earth’s.
- Earth’s rocks and land, water, air, and living things can be studied as connected groups called Earth’s spheres.
- Earth’s spheres affect one another. Rain falls from the air, water flows over land, and plants use water to grow.
Vocabulary
- Atmosphere: The layer of gases surrounding Earth.
- Geosphere: Earth’s rocks, minerals, and nonliving land materials, including the layers inside Earth.
- Hydrosphere: All of Earth’s water, including oceans, rivers, ice, and water underground.
- Biosphere: All the living things on Earth and the places where life is found.
Discussion Questions
- Living things are made of combinations of the other three spheres. Does that mean life is just a very organized arrangement of rocks, water, and air?
- Earth has a moderate atmosphere. Venus has an extremely thick one. Mars has almost none. What might cause those differences?
- If the four spheres are always interacting, what do you think would happen to the biosphere if the hydrosphere disappeared?