With Earth’s surface already in darkness, the setting sun, the cloud masses, and the sideways viewing angle make a powerful image of the kind that astronauts use to commemorate their flights.
Thin layers of lighter and darker blues reveal the many layers of the atmosphere. The lowest layer—the orange-brown line with clouds and dust and smoke—is known to scientists as the troposphere, the layer of weather as we experience it. It is the smoke and particles of dust in the atmosphere that give the strong red color to sunsets.
Astronauts see the atmosphere like this roughly every 90 minutes, as they view sixteen sunrises and sixteen sunsets every day.