There is a Lunar Eclipse on December 21st (Winter Solstice) The eclipse will begin just after 10:30pm on Dec 20th and take 3-5 hours to complete the cycle. A lunar eclipse occurs when the shadow of the Earth (umbra) passes in front of the earth. Winter solstice is the day with the fewest hours of daylight. After winter solstice days will get longer until summer solstice. Both events occurring on the same day is very rare the last time this happened was almost 400 years ago. The next lunar eclipse visible to North America will be in April 2014.