On May 26, renowned photographer Aaron Watson was in Colorado, aiming to capture the Milky Way and airglow. To his surprise, he recorded ghostly green ripples in the sky—an extraordinary sight usually hidden from our eyes.
These green ripples are a result of a phenomenon called airglow. This faint light comes from Earth’s upper atmosphere when molecules absorb energy from sunlight during the day. After sunset, they slowly release this energy as light. Specifically, the green color is due to oxygen molecules located about 62 miles above the Earth. These molecules recombine and emit light through a process known as chemiluminescence. “I have seen airglow before, but seeing it directly overhead and in motion is rare,” Watson shared.
During the day, sunlight splits oxygen (O₂) into individual atoms. These atoms store energy for several hours. When they reunite to form O₂, the stored energy is released as faint light, resulting in the enchanting green glow. This glow is incredibly subtle, often a billion times fainter than sunlight, making it hard to see without assistance at night.
The ripples in Watson’s footage were triggered by gravity waves from thunderstorms. These waves ripple through the upper atmosphere, disturbing the airglow layer and creating visible patterns that resemble water ripples. Watson noted that the ripples flowed from south to north, originating above storms to the south. While these waves were invisible to the naked eye, they made the sky appear slightly brighter, especially near the horizon.
Watson’s timelapse, taken around 3:30 a.m. and lasting about 30 minutes, displayed these ethereal movements. His camera was sensitive enough to pick up the delicate green waves, revealing a part of the night sky that most people never see.
Astrophotography like Watson’s opens doors to discovering unseen cosmic and atmospheric wonders. With the right equipment, anyone can capture beautiful sights, including airglow and the Milky Way.
In recent years, interest in astrophotography has surged, partly fueled by social media. More people are sharing their celestial captures online, creating communities that celebrate these hidden beauties. According to a survey by AstroBin, a popular astrophotography platform, 65% of users reported feeling a deeper connection to the universe through photography.
If you’re intrigued by the beauty of the night sky, check out Watson’s work on his website, Skies Alive Photography, where he showcases the hidden wonders above. His experience reminds us that patience, skill, and a pinch of luck can help reveal the invisible beauty of our atmosphere.