I'm sorry I don't have a picture, but if you watched the skies on Monday evening (Dec. 10) you know what I'm talking about.  I live in Welland, Ontario about twenty minutes west of Niagara Falls.  Around 6:45 I noticed a huge flaring comet in the western sky about 45 degrees above the horizon.  By 7:00 it had moved toward Cassiopeia and had grown much fainter and by 7:20 it was within Cassiopeia, but was barely visible.  Thanks to your updates. I've been watching Holmes for a few weeks.  But this was on the other side of the sky from where I expected Holmes to be at that time.  What was it?  (I was running in and out of our Church as my kids were rehearsing for next weeks pageant.  Of course, I immediately thought of the star of Bethlehem.)

By late December, the Sun has moved into the stars of the constellation Sagittarius. If we could see the stars against the bright glare of daytime, we would see the Sun passing through the widest part of the Milky Way. Each year, on or about December 21, the Sun reaches the southern extreme of it's annual cycle through the constellations. This point in the sky is called the winter solstice. And the day on which the Sun reaches this point is also called the winter solstice for people north of the equator.

The word "solstice" comes from the Latin words Sol (which means "Sun") and stitium (which means "stand"). So the solstices are the points in the sky where the Sun reaches its southern limit, and "stands" for a time before heading north again. The Ancient Greeks called this point "The Tropic" from the Greek word tropos, which means "turning point," since the Sun would turn north in its motion through the sky.

On the winter solstice, the Sun reaches a declination in the sky 23 1/2 degrees to the south of the celestial equator.  In the celestial coordinate system, "declination" is the celestial counterpart of latitude, so a particular declination in the sky corresponds exactly with the same latitude on the Earth. This means that the Sun passes directly overhead on December 21 for people living at a latitude of 23 1/2 degrees south. When the Sun is overhead, the shadows disappear underneath since the Sun's rays shine directly down from above.

Ironically, this name is centuries out of date. In the days of Jesus and the Roman Empire, the solstice point was in the constellation Capricornus. But over the last 2000 years, the solstice point has drifted into the constellation Sagittarius. This is the result of a phenomenon called "precession," a slow wobble of the Earth's axis due to the influence of the Moon's gravity. So the name of the southern tropic should properly be called The Tropic of Sagittarius. But for some strange reason, in Classical Astronomy, old traditions die very hard!

((( ACTIVITY!!! ))) Look up "precession" in an encyclopedia or on the Internet. You can start with the SkyWise comic strip on the subject.

As you might conclude, The Tropic of Cancer is the northern extreme of the Sun's annual motion, which the Sun reaches on the summer solstice, on or around June 21. So the climate zone we call "The Tropics" is astronomically defined as the region where the Sun passes directly overhead, and where noon shadows will disappear on at least one day of the year. The Sun's annual motion makes up the cycle of "the Rolling Year," the cause of the passage of the seasons, and by which we measure the lengths of our lives.

On the winter solstice, everyone south of the equator experiences the longest day of the year. On this day, the Earth reaches a point in its orbit where the South Pole is inclined toward the Sun. On most of the southern continent of Antarctica, there is continuous 24 hours of sunlight. The limit of continuous solstice daylight is the Antarctic Circle, latitude 66 1/2 degrees South, 23 1/2 degrees latitude from the South Pole. If one could be at the Antarctic Circle, one would see the Sun circle the sky and touch the northern horizon at midnight.

The length of solstice daylight grows shorter as one moves away from the Antarctic Circle. The days are longer in the southern temperate regions than the southern tropics. For example, the longest day is longer in New Zealand than in South Africa or northern Australia. And on the equator, every day is an equinox, with twelve hours of daylight and twelve hours of night time.

* Northern Skies *

In the lands north of the equator, the winter solstice is the shortest day of the year. And though the days are short, there is longer daylight in the northern tropics than the northern temperate areas.

In North America and Europe, the winter solstice is traditionally observed as the first day of winter. For locations near the latitude 40 degrees north, the days are about nine hours long and the nights are about fifteen hours long. But the days are somewhat longer in Florida, Texas and southern California. Similarly, the daylight is shorter in the northern states and up into Canada.

For people all over the world, the Sun rises and sets at its farthest point along the horizon to the south. For people in the southern hemisphere, the noon shadows are the shortest since the Sun is at its highest overhead at noon. But for folks in the northern hemisphere, the Sun hangs at its lowest above the southern horizon, and the noon shadows are at their longest of the year.

In the northern polar regions, the Sun does not rise on the winter solstice. For folks on the Arctic Circle, in places like Alaska, Northern Canada, and Scandanavia, there is a long twilight beginning in the late morning. If a clear horizon is available, the Sun can be seen grazing the southern horizon at noon, only to set again, with another long twilight in the early afternoon.

Way up at the North Pole, it is the "midnight" of the long Arctic night. The Sun sets on the autumnal equinox, followed by a couple months of twilight, with full night darkness commencing in mid-November. After the winter solstice, the Sun will begin to rise again, and the Arctic "day" will begin again on the vernal equinox in March.

After the winter solstice, the Sun moves north again, and will rise and set further along the northern horizon for everyone all over the world. As we enter the New Year, the days will grow shorter for people in the southern hemisphere, and longer for folks in the northern hemisphere. And in June, the Sun will turn south again, following the seasonal cycle that will continue "while the earth remaineth" (Gen 8:22).