The Earth's Layers Lesson #1. The Four Layers. The Earth is composed of four different layers. Many geologists believe that as the Earth cooled the heavier, denser materials sank to the center and the lighter ... The crust and the upper layer of the mantle together make up a zone of rigid, brittle rock called the Lithosphere . read more
If nothing else, check an encyclooedia or Wikipedia Here is an answer from Oregon State University The Earth's Layers Lesson #1 This page may be out of date. Save your draft before refreshing this page. read more
Perched above the other subsystems you'll find the atmosphere. Essential to life on the planet, it only makes up about 0.07 percent of the Earth's mass. The atmosphere contains several layers including the troposphere, a layer that interacts with the other subsystems. read more