Why does the moon look red during a total lunar eclipse?Posted: June 15, 2011
From Deborah Byrd at EarthSky.org:
During a lunar eclipse, you’ll see the Earth’s shadow creeping across the moon’s face. The shadow will appear dark, like a bite taken out of the moon’s face, until the shadow completely covers the moon. Then, during the breathtaking moments of totality, the shadow on the moon’s face often often suddenly changes. Instead of dark, it appears red. Why?