Two of Earth's most colourful upper atmospheric phenomena, aurora and airglow, met in this stunning photograph shared by NASA. Taken by an astronaut on the International Space Station, the photograph shows the easily-recognisable green of aurora borealis intersecting with the wispy, golden-ish band of airglow above the Earth.
"Aurora, meet airglow," wrote the US space agency while sharing the spectacular image on Instagram a few hours ago. Describing them as two of Earth's most colourful upper atmospheric phenomena, NASA wrote: "Aurora and airglow met just before dawn in this March 16 photo shot by an astronaut on the International Space Station."
The photo was taken as the ISS passed south of the Alaskan Peninsula. Below the aurora and airglow, sparkling lights from British Columbia and Alberta, Canada, dotted the skyscape, as stars lit up the early morning sky above.
"Wavy green, red-topped wisps of aurora borealis appear to intersect the muted red-yellow band of airglow as the ISS passed just south of the Alaskan Peninsula," the agency wrote.
NASA further explained that though they appear similar, aurora and airglow are formed by different processes. While auroras stem from interactions between solar energy and Earth's magnetic field, airglows are "the emission of light from chemical interactions between oxygen, nitrogen, and other molecules in the upper atmosphere."