Airglow is the light of excited atoms high in Earth’s atmosphere. It’s usually too faint for the eye alone to see. But under very dark skies, photographers can capture it. Here’s how NASA’s Earth Observatory describes airglow:
The phenomenon typically occurs when molecules (mostly nitrogen and oxygen) are energized by ultraviolet (UV) radiation from sunlight. To release that energy, atoms in the lower atmosphere bump into each other and lose energy in the collision. But the upper atmosphere is thinner, so atoms are less likely to collide. Instead, they release their energy by emitting photons. The result is colorful airglow.
But some collisions can also create airglow. In fact, airglow is more common during solar maximum. That’s because the solar activity heats the upper atmosphere, which causes more collisions. Specifically, it causes more collisions that result in greenish light. Spaceweather.com said:
Although airglow does not require solar activity, there is a strong link to the solar cycle. As long ago as 1935, Lord Rayleigh realized that airglow peaks during years around solar maximum. Modern studies (e.g., 2011 and 2015 have confirmed the effect. Airglow is up to 40% brighter when the sun is most active.
Watch a video on airglow
And here’s another view of airglow from the International Space Station.
If you have a recent photo of airglow to share, send it to us!
View at EarthSky Community Photos. | Julie Machado captured this image from New Zealnd on November 16, 2025. Julie wrote: “This photo shows the faint red emission of the Gum Nebula above the mountains in Coromandel, New Zealand. The nebula is extremely large and very dim, but long-exposure imaging can reveal parts of its structure. The green band near the horizon is natural airglow. The sky and foreground were photographed on the same night from the same spot, with the sky taken on a tracked exposure and the landscape untracked. The image reflects the scene as it appeared that night.” Thank you, Julie!View at EarthSky Community Photos. | Meiying Lee in Mount Cook National Park, New Zealand, captured the Milky Way on March 19, 2026. Meiying wrote: “The southern Milky Way rises directly from the horizon, shining with remarkable clarity. On the right side of the sky, 2 faint, cloud-like patches stand out. These are the Large and Small Magellanic Clouds, iconic features of the Southern Hemisphere. Near the horizon, subtle hues of green and red glow softly. This is airglow, quietly revealing just how pure and transparent the sky is here.” Thank you, Meiying!View at EarthSky Community Photos. | Paolo Bardelli of Switzerland captured the sun’s counterglow – or gegenschein – on November 2, 2024, and wrote: “The elusive gegenschein phenomenon captured on a clear night from the Simplon Pass in Switzerland. The antisolar point is located in the top right image, barely visible as a very faint and diffuse nebulosity extending over 20° in a sky with green and orange airglow. The image was highly contrasted to accentuate the phenomenon.” Thank you, Paolo.
Bottom line: Airglow is a light that occurs high in Earth’s atmosphere. It’s usually too dim to see with the eye, but photographers can capture glorious photographs of it.
Kelly Kizer Whitt - EarthSky’s nature and travel vlogger on YouTube - writes and edits some of the most fascinating stories at EarthSky.org. She's been writing about science, with a focus on astronomy, for decades. She began her career at Astronomy Magazine and made regular contributions to other outlets, including AstronomyToday and the Sierra Club. She has nine published books, including a children's picture book, Solar System Forecast, and a young adult dystopian novel, A Different Sky.
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