Behind the earth is its shadow, darkened air created when the body of the earth blocks the sun. Behind the earth is its shadow, the one we call night.
Earth rolls into darkness at one thousand miles an hour at the equator, zero miles an hour at the poles – where darkness is caused by tilt rather than rotation.
As the world of light is eclipsed by night, a soft black shroud sops the last light from the shadow’s rim. Colors fade. Green and white become teal blue, deepen to steel blue, to blue black, to black. Lights appear, the human web spun over the earth. Deserts and snow-covered landmasses are the only parts of the earth illuminated solely by moonlight. The Sahara sleeps alone.
NASA video of the earth at night: