9/22/2005: Red flash moon

[tw]

Originally Posted by mitheral

I think tw is talking about illumination of the moon when it is in earths penumbra or during an eclipse when some to all of the light hitting the moon has been filtered thru the earth's atmosphere.

Correct. The moon would be completely dark. But sunlight passing through the earth's atmosphere is refracted. Lowest frequency light is bent most which is why the moon glows red. Intensity of that light measures atmosphere clarity. This intensity must be compensated for by adjustments in the moon's orbit (apogee and perigee, etc), variation in sun's intensity, how the light is measured, etc. These experiments have been ongoing for decades. I thought I had posted a description previously in The Cellar. Apparently not.