Dec. 31, 2:13 p.m. EST -- Full Long Night Moon.

Singing to the Moon bikesnapper

Nights are at their longest and darkest. The term Long Night Moon is a doubly appropriate name because the midwinter night is indeed long and the moon is above the horizon a long time. The midwinter full moon takes a high trajectory across the sky because it is opposite to the low Sun. This is the second time the moon turns full in a calendar month, so it is also popularly known as a "Blue Moon." Full moons occur on average each 29.53 days (the length of the synodic month), or 12.3683 times per year; so months containing two full moons occur on average every 2.72 years, or every 2 years plus 8 or 9 months. There will be a partial lunar eclipse that will be visible from Europe, Africa and Asia with this full moon. At its maximum 7.6-percent of the moon's diameter will become immersed in the Earth's dark umbral shadow.