Snapped off the coast of Australia by an Expedition 28 astronaut on the International Space Station, this is a beautiful photograph illustrating atmospheric layers. The black at the bottom of photograph is the Earth, followed by saturated orange troposphere illuminated by a setting sun. The troposphere is the lowest and densest atmospheric layer. It abruptly transitions into the tropopause, the blah-coloured boundary between the rich orange and blue layers. Finally, the silvery-blue noctilucent clouds extend far above in the mesosphere.

A similar view, minus the moon, was captured from a terrestrial viewpoint in Soomaa National park, Estonia. The noctilucent clouds reflecting off the bog glow from the high-altitude ice crystals reflect sunlight long after local sunset.


Photography credit: NASA (top) and Martin Koitmäe (bottom).