Astronaut Reid Wiseman recently captured a beautiful shot of the Earth’s atmosphere from the International Space Station (ISS). Wiseman used a three-second shutter exposure at night to demonstrate “how crazy our atmosphere really is.” Reddit user smsmkiwi broke down what the image is actually showing in an incredibly informative comment.
The orange and green arcs are layers of glowing gas are called airglow. Each layer glows at a specific wavelength or band of wavelengths. The broad orange layer at the top is due to atomic oxygen from ~250 km altitude. The narrow green layer is also atomic oxygen and that originates from near 96 km altitude. Just below that is another orange layer due to atomic sodium from meteors burning up in the upper atmosphere at ~90 km altitude. Maybe a contribution in that layer by hydroxyl from 87km also. This images was taken from the space station (ISS) during the night portion of it’s orbit. The earth’s surface shows cloud lit by moonlight.
— Reid Wiseman (@astro_reid) August 18, 2014
photo by Reid Wiseman