Taken from the International Space Station, this picture of the Earth's moon shows the planet's horizon, its orange-colored troposphere, the boundary between the troposphere and the stratosphere called the tropopause, and silvery-blue noctilucent (night-shining) clouds. The photograph was taken by Expedition 28, whose members returned to Earth on September 16th.
We want to hear what you think about this article. Submit a letter to the editor or write to firstname.lastname@example.org.
Rebecca J. Rosen is a senior editor at The Atlantic, where she oversees the Family and Education sections.