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  • The Winter Solstice 
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 Welcome to the Classical Astronomy Update!

 

 

Signs of the Seasons 

The Winter Solstice
 I thank Thee, Lord! The whiteness
Of winter on my heart
Shall keep some glint of brightness
Though sun and stars depart.

-- William James Linton (from The Old Farmer's Almanac, 1903)

 

During December, the Sun passes through the stars of Sagittarius the Teapot.  This constellation is therefore not visible at this time, hidden behind the Sun's bright glare.  The Sun is now in the southernmost portion of its annual path through the zodiac constellations, and thus rises and sets far to the south. 

 

(from Signs & Seasons: Understanding the Elements of Classical Astronomy) 

 

On about December 21 each year, the Sun reaches the southernmost extent of its annual cycle. This day is knowns as the winter solstice and is traditionally regarded as the official "first day of winter" for observers in the northern hemisphere. 

 

On this day, the Sun is at its lowest point of the year in the noon sky as seen from the northern latitudes.  The Sun never gets too high off the ground at noon as seen from the temperate zone. On this day you can measure the longest noon shadows of any day of the year. 

 

After reaching its most southerly declination on the winter solstice, the Sun will appear to head north again, following its annual cycle through the seasons. In the coming months following December, keep your eye on the noon shadows, and notice how the they get shorter as Sun moves higher to the north in the noon sky, until reaching its northern maximum on the summer solstice in June.

 

On the winter solstice, since the Sun rises and sets very far to the south, it is not in the sky for very long. For this reason, the winter solstice is also "the shortest day of the year" since the length of daylight is shortest for people living north of the equator.

 

Here in Cleveland, the daylight on the shortest day lasts about 9 hours. Cleveland is near latitude 40 degrees North, along with many other large American cities, such as New York, Washington DC, Chicago, and San Francisco. So the length of daylight is about the same for these cities as well.

 

However, the length of winter daylight is even less for places further north. At the Arctic Circle, the Sun rises directly in the south at noon and immediately sets.  In Alaska and Iceland, daytime is simply an extended twilight on either side of the noontime sunrise/sunset, and the Arctic nights of early winter are long and dark.

 

(from Signs & Seasons: Understanding the Elements of Classical Astronomy) 

 

Meanwhile, December 21 is the summer solstice and thus the longest day of the year for people in the southern hemisphere. Folks in New Zealand, Australia, and South America are enjoying warm days and late sunsets we northerners shiver in the dark!  But please don't envy them, they get their payback in June since their shortest day of the year is our longest!

 

The solstices and other aspects of the Sun's annual cycle are explained in detail in Chapter 5 of our Signs & Seasons astronomy curriculum.  Remember, S&S isn't just for homeschool students!  An increasing number of parents (especially the dads) are reporting that they are also learning a lot!   

 

 

Astronomy Topics 

Christmas Articles from the Archives
The Classical Astronomy Update has grown so much in the last year, and there may be a number of people that missed some of our past articles and have not visited our Sky This Month page or explored our extensive archives (currently up to about 300 articles).  If you're new to the Update, be sure to check out these articles on the subject of Christmas.....

 

Some Christmas Sources

Though the Gospels are our primary sources for the story of the birth of Jesus, this article takes a look at some secular historical sources that support the Biblical account of the Nativity.

 

Christmas Possibilities

As homeschoolers, we all hope to raise our kids to be discerning, to get their facts straight, and to rely on Scripture and reliable sources of secular authority for their facts.  We can start by examining some of our cultural traditions that surround Christmas.  Many Christmas traditions are not well supported by evidence, such as the Bible or other reliable sources. As homeschool families, we all want to cultivate critical thinking in our kids, and good lessons can be had by considering some of the facts and fancies about Christmas.

 

Is Christmas Pagan?

While we're on the subject of facts, evidence and critical thinking, this article from our "Pagan Influences?" series examines some of the "urban legends" about the origins of Christmas that commonly circulate at this time of year.  Is Christmas really a thinly veiled pagan feast of Sun worship?  If you think you already know the answers, see if you've ever considered these facts. 

 

It's hard to believe that 2008 is over already.  It's been a somewhat difficult year for our family, but the LORD has been good and has continued to bless us with our basic needs.  As He clothes the lillies of the field and feeds the sparrows of the air, let us enter 2009 with a heart of gratitude.  The Ryan Family wishes your family a pleasant and blessed Christmas season.