I am aware that the sun looks yellow from earth due to the atmospheric scattering of short wavelength (blue) light - the same reason that the daytime sky is blue. I am also aware that from space, where this effect does not occur, the sun appears white.
[a] Why, then, do the stars appear white when viewed through earth’s atmosphere? I understand that from such distances, the little bit of blue light that would be scattered wouldn’t light the nighttime sky or make it appear blue in color. But shouldn’t the little bit of starlight that passes through the atmosphere be yellowed like sunlight?
[b] Also, since twinkling of stars is an atmospheric effect like the shimmering mirages on the desert or those over hot asphalt - worse the warmer the night and the more active the atmosphere - why doesn’t the midday sun twinkle or shimmer when seen through our warm daytime atmosphere? Even low on the horizon when it is red and ditorted, it's still not "twinkling." Why just distant stars?
2007-11-27
09:09:09
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5 answers
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asked by
Yaybob
7