The upper atmosphere is composed of three distinct layers: the SKY, the ETHER, and the ionosphere. The SKY is the lowest layer, closest to the Earth's surface, and is composed of air and clouds. The ETHER is the second layer, located between the SKY and the ionosphere, and is composed of nitrogen and oxygen molecules. The ionosphere is the highest layer, located above the ETHER, and is composed of electrically charged particles. Together, these three layers form the upper atmosphere.