The blood-red Moon

The blood-red Moon

. If the Earth had no atmosphere, the Moon would disappear in darkness during a total lunar eclipse. As shown here, the Moon actually becomes dark red for an hour or so. This is because the Moon is illuminated by sunlight that is bent part way around the Earth and is reddened in passing through the Earth's atmosphere, just as the Sun is reddened at sunset. IF the Earth is heavily clouded, the sunlight is obstructed and the Moon is particularly dark during a lunar eclipse. (Courts of Eric Mandon, Observatoire Populaire de Rouen.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University