This year's December solstice is Wednesday, and here are seven things you may not know about it.
1. It's the winter and summer solstice
Here in the Northern Hemisphere, we call it the winter solstice while it's the Southern Hemisphere's summer solstice.
2. A single moment in time
The December solstice is only a moment, not an entire day. It's the exact moment when the sun's rays shine directly on the Tropic of Capricorn. The June solstice, by contrast, is the exact moment when the sun's rays shine directly on the Tropic of Cancer.
3. It's the first day of winter
Similarly, the solstice is the first day of astronomical winter in the Northern Hemisphere. For meteorologists, however, meteorological winter started way back on Dec. 1.
4. It's the shortest day of the year (and longest night)
The winter solstice has the least amount of daylight and the most amount of night the entire year. However, the earliest sunset and the latest sunrise don't happen today.
5. It's not always on same day
The December solstice can land on Dec. 20, 21, 22 or 23. However, the day usually lands on December 21 or 22.
6. The Earth isn't farthest from the sun
During the Northern Hemisphere's winter, the Earth is actually closest to the sun. It's during the Northern Hemisphere's summer when the Earth is farthest from the sun. The seasons have very little to do with the Earth's distance from the sun and more to do with its tilt on its axis.
7. Daylight increases faster farther north
More northern latitudes will see more and more daylight faster than any places closer to the equator, but that's also because the amount of daylight near the equator doesn't widely vary from season to season.
This year, the December, or Winter, solstice occurs at 5:44 a.m. EST. It'll be another 6 months before the next solstice in June — the longest day of the year.