Airglow is the name of an amazing phenomenon that takes place in our upper atmosphere. It typically happens when molecules become energized by UV radiation from sunlight. To release this energy, atoms located in the lower atmosphere bump into each other. But because the upper atmosphere is thinner, atoms are less likely to collide. Instead, they release this energy by emitting photons, resulting in the vivid colors we call airglow.

Airglow is usually too faint to be seen by the naked eye on Earth, but it is possible to observe either from orbit or on the ground with dark skies and a sensitive camera. Photographers are sometimes able to capture tremendous images of the phenomenon.

Unlike auroras, which are caused by solar particles interacting with Earth's magnetic field and appear as dancing curtains of light, airglow creates a steady, subtle glow that can appear in different colors depending on which gases are involved. Oxygen typically produces green and red hues, while sodium creates a warm yellow glow, and hydroxyl molecules contribute to infrared emissions. This gentle luminescence occurs continuously around the globe, making our planet glow softly in space like a giant night light—a fact that astronauts on the International Space Station get to witness firsthand during their orbits.

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Senior writer Chris DeWeese edits Morning Brief, The Weather Channel’s weekday newsletter.