Winter Solstice -- December 21, 2013

The shortest day of the year -- Winter Begins at 12:11 p.m. Eastern Time; DETAILED feature story from CS MONITOR dot-com (online Christian Science Monitor) -- today's online article: "Up until winter solstice, the sun is moving southward from day to day. As it approaches solstice its southward march slows down," says Benjamin Burress, an astronomer at the Chabot Space & Science Center in Oakland, California. At the solstice the sun stops going south and pauses, motionless. "Then after solstice, it is again moving northward in the sky each day," he says. Solstice means "stationary sun." The solstice occurs because the Earth is tipped on its axis 23.5 degrees. In the northern hemisphere in the summer, the axis is pointing its most toward the sun on June 21. On that day the most light reaches us and we experience the longest day of the year and warmer temperatures: the summer solstice. The reverse is true on Dec. 21. Then the axis is pointing its most away from the sun, bringing less light and colder temperatures. That is the winter solstice, the longest night of the year. It's the opposite in the southern hemisphere, where Dec. 21 marks the longest day of the year and June 21 the shortest. The midpoints, on March 20 and Sept. 22, are known as the equinoxes. On these days the axis is exactly in between and night and day are each the same length, 12 hours.