December 21, 2010 is the winter solstice this year, the shortest day of the year, and the first day of winter. the moon will be full. In the early morning, the full moon will be passing directly through the northern half of the darkest part of the Earth’s shadow (the umbra), i.e., a full lunar eclipse will be visible to almost all of North America! The eclipse starts at 12:30 AM Eastern Standard Time (Tuesday morning).