The above image was taken on the evening of February 20, 2008 just after the Moon entered the totality phase of the eclipse.  This phase of the eclipse lasted almost an hour.  This eclipse marked the last total eclipse of the Moon until December 21, 2010.  A total Lunar eclipse only occurs when the Moon passes through the densest part of the earth’s shadow called the Umbra.  Since the orbit of the Moon is tilted about 5 degrees to the plane of the Earth’s orbit around the Sun, the Moon does not pass through the Umbra during most of its orbits around the Earth.  When all the orbits “sync” and the Moon passes through the Umbra shadow, we see the spectacular event of a Total Lunar Eclipse.  All of the sunlight is not blocked from the Moon during a total eclipse.  Some light still reaches the Moon and usually results in a reddesh or orange color.  The sunlight is being refracted through, and filtered by, the Earth’s atmosphere.  This results in most of the blue light being attenuated and therefore the red hue we observe during the eclipse.

¹ http://sunearth.gsfc.nasa.gov/eclipse/LEmono/TLE2008Feb21/TLE2008Feb21.html