It is going to be dark Tuesday night. With the perfect storm of a full lunar eclipse occurring on the shortest day of the year, that night is going to seem particularly long and dark. While there will be a full moon the night of the 21st that will brighten things up, the eclipse is going to remove that light source from the night sky for some time. If you live in North America, you will be able to see this. If you live in Europe, you will not.
The winter solstice is the shortest day of the year if you live north of the Equator. That same date is defined as the summer solstice if you live south of that imaginary line. The sun will be at its lowest point in the sky during the day and, thus, will rise later and set earlier than other days. Of course, after December 21, the Northern hemisphere will be back on the way to longer days and more light as the sun rises earlier and sets later, ever so slightly each day until the Northern hemisphere experiences its summer solstice.
It might seem unexciting, but the next time a full moon occurs on a solstice is Dec. 21, 2094! And the last time this happened was on Dec. 21, 1638.