Listening practice: The night sky that glows

At night, even far from city lights, Earth is not completely dark. Along the planet's curved edge, a thin band can glow green, yellow, or red. From the ground, it is usually too faint to notice. From space, the band becomes easier to see. This quiet light has a name: airglow, also called nightglow. NASA describes it as light produced by chemical reactions high in Earth's atmosphere. The source is not a distant star and not a lamp on the ground. It is the atmosphere itself, releasing a small amount of light after energy has been added to its atoms and molecules. Today we will follow that light from its chemistry to its moving patterns, and we will ask why it can look a little like an aurora.