Just as the sun sets on this Christmas Eve, so did the sun set on the moon during the Winter Solstice of 2010 when a lunar eclipse occurred at the same time.  As the Earth moved into the path of the Sun’s rays, it casts it’s shadow on the moon.  Once the moon becomes fully eclipsed, covered by shadow, the moon takes on a redish glow.  Earth’s thick, dust-filled atmosphere filters the sunlight shining through it, resulting in the rusty hue of a total lunar eclipse which is also the same reason the sun looks reddish during sunrises and sunsets.  It makes for quite an interesting view of the moon.  It almost looks like Mars!