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Why Does the Full Moon Look Bright When Viewed From Earth But Dim When Observed From Space?

-- | February 24, 2016

Question: Why does the Moon look quite bright from Earth when it is full, but quite dim and faint when observed from space? — Sam

Answer: I think that this might be a “perspective” difference that you are seeing. When you look at the full Moon from Earth you are looking at a bright object which is, by far, the brightest object in the night sky. This gives the full Moon the illusion of being *really* bright. When viewed from space, the Moon is just one of three objects which appear bright, the other two being the Earth and the Sun. One then perceives that the Moon is bright, but not excessively brighter than the nearby Earth, for example. Finally, since you are comparing the image that your eyes see when viewing the full Moon from Earth with a photographic image of the Moon from space there could be dimming factors introduced by the photographic process.

Jeff Mangum

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