Astrophotographer Daniel McVey sent in this photo of Orion taken in Colorado, Dec. 11, 2012. He writes: "Snow covered trees and Orion high in the sky are sure signs that winter has arrived in Summit County, Colorado."
At 6:12 a.m. EST on Friday (Dec. 21), the sun will reach a point where it will appear to shine farthest to the south of the equator, over the Tropic of Capricorn, thus marking the moment of the winter solstice — the beginning of winter.
Since June 20, the altitude of the midday sun has been lowering as its direct rays have been gradually migrating to the south.
The sun's altitude above the horizon at noontime is 47 degrees lower now, compared to six months ago. Your clenched fist held at arm's length measures roughly 10 degrees, so the sun at midday is now nearly "five fists" lower in the southern sky compared to on June 21.
For the rest of the story: http://www.livescience.com/25749-winter-solstice-sun-altitude-explained.html