No sudden, sharp boundary marks the passage of day
into night in
this gorgeous view of ocean and clouds over our
planet Earth. Instead, the shadow line or
terminator is diffuse and shows the gradual transition to darkness we experience as twilight. With the Sun illuminating the scene from the right,the cloud tops reflect gently reddened
through the dusty troposphere, the lowest layer of the planet's nurturing atmosphere. A clear high altitude layer, visible along the dayside's upper edge,
sunlight and fades into the blackness of space.