Earth at Twilight
Explanation:
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.
APOD presents: Astronomy Pictures of the Year for 2007
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
