Monday, October 1, 2007
Red Moon at Night, Motorists Take Fright
The moon was like our own private lunar eclipse.
the disk was full, and a dark febrile red-maroon.
The riddle was that no lunar clipse was expected that night. There had been one a few days earlier, as the moon swept through the very narrow shadow cast by Earth.
Refracted light passing through Earth's atmosphere paints the moon red. Bluish light is scattered and longer wave-length red light penetrates our atmosphere and hits the moon.
But we were driving though Pennsylvania perhaps 10 or 11 p.m. and the moon was rising. It was about 20 degrees above the horizon and as weird-looking as it ever gets.
The moon hung like a blood blister. Out satellite even seemed ominous, though we knew that lunar signs do portent disaster. (Do they?)
A cell phone check confirmed that no one else was seeing a lunar eclipse.
What was going on?
The only good explanation was that we were looking at the moon through an extremely thick layer of atmosphere, which was exerting its own optical effects. Specifically, the atmosphere was scattering blue, as it always does, and letting red through.
The red was dimmed by tons of soot, dust, water vapor, volcanic ash, fly ash, meteorite dust, smog,and smoke.
And that's the stuff we can see. Even if we got rid of carbon dioxide and the greenhouse effect, it looks like we'd still be in trouble.