Earth at Twilight
No sudden, sharp boundary marks the passage of day
into night in
this gorgeous view
of ocean and clouds over
our fair
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
sunlight
filtered
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,
scatters blue
sunlight and fades into the blackness of space.
This picture actually is a single digital
photograph taken in June of 2001 from the
International Space Station orbiting
at an altitude of 211
nautical
miles.