An incredible video captured from the International Space Station shows an aurora from above, rippling with the unusual green light that has drawn our attention to the skies throughout time.
NASA astronaut Don Pettit shared the video from his orbital vantage point on January 6, capturing the “intensely green” ribbons rarely seen from above.
Flying over aurora; intensely green. pic.twitter.com/leUufKFnBB
— Don Pettit (@astro_Pettit) January 6, 2025
Our Sun is having a pretty tumultuous time at the moment, unleashing a series of huge eruptions, flares, and coronal mass ejections in recent weeks.
Events known as coronal mass ejections – huge eruptions of plasma that take hours to days to billow out through the Solar System – are ultimately responsible for the magnificent light show in our skies. Charged particles from these eruptions zoom through space before slamming into Earth’s magnetic field, which directs the rain of ionic dust towards our planet’s poles into the gases making up the atmosphere.
Swept up in the excitement, atoms and molecules of different elements spill forth a light show in hues of greens, pinks, and blues. These displays light up in ribbons that trace the magnetic field lines that govern the solar winds towards the ends of the Earth.
Those colors confounded scientists during the 19th century, who tried to reconcile the lights above with what they were seeing in their electrified tubes of gases in the laboratory. Though early observations suggested the stunning green may be the result of hydrogen, or even an unknown hypothetical element belonging to the Sun called “aurorium.”
Oxygen was proposed as a culprit, yet its stubborn refusal to glow green under less natural conditions in the hands of physicists made it a problem for decades.
Unlike many elements which shine a fraction of a second after being struck, atomic oxygen ‘relaxes’ at a relatively sluggish pace of almost a whole second, thanks to the unconventional way its electrons settle back into place. This gives the environment plenty of time to steal its energy and prevent it from showing its true colors.
In the crowded conditions close to Earth’s surface, oxygen barely has time to glow. At a critical point around 100 kilometers (about 60 miles) overhead, the element suddenly has enough room, creating a “brilliant green line” above which the skies turn so otherworldly.
This generally occurs at altitudes up to 300 kilometers. Higher than that, and the pressure becomes so low that oxygen’s forbidden glow can take all the time it needs, delivering a deep red light.
It’s not the first time we’ve seen this stunning phenomenon from above: a photo from ESA astronaut Thomas Pesquet took our breath away in 2021, and in 2023, astronauts Josh Cassada of NASA and Koichi Wakata of the Japan Aerospace Exploration Agency shared equally awesome views.
Nor will it be the last: as we climb towards the next solar maximum equipped with better satellite and camera technology than ever, we’ll no doubt continue to see auroras dancing in the sky in a light we never imagined.
