In Earth’s upper atmosphere, ultraviolet light from the Sun ionizes atoms and dissociates molecules at heights between 40 and 200 miles (64 and 322 kilometers) above the planet’s surface. When the fragments collide and recombine, some atoms and molecules are left with excess energy, which they release as light, known as airglow. Airglow hampers optical telescopic observations on Earth by reducing the apparent contrast between stars and space. What types of atoms are involved in the phenomenon? Discuss