The Lunar Eclipse

A photo collage of 13 separate images shows the path of the moon during the lunar eclipse as seen from Calgary, Alberta on Tuesday, December 21, 2010. This eclipse is the first in 372 years to occur on the winter solstice, the first day of winter marked by the shortest day and longest night of the year. A lunar eclipse occurs when the moon, Earth, and the sun all line up, with Earth in the middle. During the eclipse, Earth's shadow is cast onto the full moon, dimming—but not completely obscuring—its surface. Unlike solar eclipses, the lunar varieties are safe to view without any special eyewear.