Credit: Image Science & Analysis Laboratory, NASA Johnson Space Center
The layered structure of Earth's atmosphere is visible in this view of a sunset over the Indian Ocean as seen from the International Space Station. The troposphere (orange) is at the bottom, above the dark limb of Earth's surface. Above it lies the pink to white stratosphere. Higher still the light blue mesosphere and beyond gradually fades to the darkness of space. An astronaut snapped this photo on May 25, 2010.