One Awesome Full Moon On the Solstice
What an event! A repetition of the coinciding of a lunar perigee and the winter solstice that has not occurred for one hundred thirty-three years.
December 22, the shortest day of the year, we commonly call the first day of winter.
In 1999 the winter solstice occurred in conjunction with a lunar perigee, that is the point in the moon's orbit that is closest to earth. The moon will appear about 14% larger than it does at apogee, that is the point in its elliptical orbit that is farthest from Earth.
Since the Earth is several million miles closer to the sun at this time of year than in summer, sunlight striking the moon is about 7% stronger which accounts for the extra brilliance. Also, this was the closest perigee of the moon that year since the moon's orbit is constantly deforming. If the weather was clear with a snow cover viewers could see clearly, even car headlights were unnecessary.
In laymen's terms it was a super bright full moon!
On December 21 in 1866 the Lakota Sioux took advantage of this combination of occurrences and staged a devastating retaliatory ambush on soldiers in the Wyoming Territory. I wonder if they expected the night to be turned into day and caught the soldiers unawares -- OR -- if the unusual light was considered another travesty brought on by the encroaching white man for which they had to be punished?