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Pale blue dot.

  1. Sep 18, 2015 #1
    Why does the Earth appear blue (mostly) when observed from outside.
    Blue light is more energetic than red and lower wavelength.
    Processes which happen on Earth seem to suggest that higher energy light arriving should be absorbed in one way or another and eventually some of it radiated away in infrared and lower wavelength.
    Why does the Earth not look red when seen from outside?
  2. jcsd
  3. Sep 19, 2015 #2


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    What does Earth's surface consist of? The reflected light is not blackbody radiation, it is reflected light.
  4. Sep 19, 2015 #3


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    As Orodruin said, it is light that is reflected from the Earth that is seen in visible light cameras, not the light emitted by the Earth.
  5. Sep 20, 2015 #4
    OK, so on the sunlight side of Earth a high proportion of all the incoming light is just reflected away and doesn't otherwise interact.
    I guess the reason why the reflected light is more in the blue end of the visible spectrum is simply because that is a just property of water - it reflects bluer light and absorbs more red.
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