Describe the three types of materials in the planetary rings that collided with the Earth during its early stages of formation. Discuss the derivation of heat energy within the internal Earth. In what way was this heat energy used in helping to generate the Earth's ordered arrangement of compositionally stratified layers? Describe each layer, from the Earth's core to the Earth's atmosphere, and relate the ultimate (original) source of each layer to the three types of extraterrestrial materials that collided with the Earth in its early stage of formation. Explain why the differentiation of Earth into these nested layers may have been necessary for life to form and evolve on our planet.