WIKIARCHIVES.SPACE

Photographed by an Expedition 7 crewmember onboard the International Space Station (ISS), this image shows the limb of the Earth at the bottom transitioning into the orange-colored troposphere, the lowest and most dense portion of the Earth's atmosphere. The troposphere ends abruptly at the tropopause, which appears in the image as the sharp boundary between the orange- and blue- colored atmosphere. The silvery-blue noctilucent clouds extend far above the Earth's troposphere. The sliver of the setting moon is visible at upper right.