The winter solstice is a time of great celebration in Antarctica, for it means we are halfway through the perpetual polar night and the Sun has begun its journey southward to reappear in the late September sky. Since the time of the earliest Antarctic explorers, the winter solstice is when our minds turn to thoughts of the coming summer and reunification with our families and friends. It is a time when celebrations are held, special meals prepared, and messages of goodwill sent from station to station.
The word solstice comes from the Latin solsititum (sol = sun, stitium = a stoppage), since the maximum noontime elevation of the Sun above the horizon appears to be the same for a few days before and after the solstice. The Earth’s rotational axis is tilted 23.5 degrees with respect to its orbital plane around the Sun. That is the reason we experience seasons on planet Earth and why, from our vantage point on its surface, the north-south position of the Sun changes over the course of a year. A solstice occurs twice a year and marks that point in time when the Sun is furthest from the equator.
For us in the southern hemisphere, the winter solstice is when the Sun is furthest north. For those in the northern hemisphere, it is the summer solstice since the seasons are reversed. The extremes of the Sun’s yearly north-south journey also mark the imaginary lines on the globe known at the Tropic of Cancer in the north and the Tropic of Capricorn in the south. Since the solstice this year occurred at 11:09am (New Zealand time) on 21 June, if one were looking up in the sky while standing on the Tropic of Cancer (23.5 degrees north) the mid-day Sun would appear directly overhead. The Earth’s tilted axis is also the reason why there is only one day and one night per year at the North and South Poles.
The winter solstice of 2010 was very special in that it coincided with a lunar eclipse. The last time this occurred on a winter solstice was almost 4 centuries ago in 1638.
The solstice has been a special time as far back as the Neolithic period, as evidenced by the physical layout of such ancient sites as Stonehenge. The winter solstice represented the reversal of the shortening of days and the lengthening of nights. The seasonal variations governed the best times to plant and harvest crops, mate animals, and ration food. With the winter solstice came final preparations for the famine months, as the months of January through April were know in the northern hemisphere. Many were not certain of surviving the winter and starvation was common.
As a result of the significant influence astronomical events had upon survival in earlier ages, holidays, celebrations, rituals, and festivals evolved to mark these important times of year. Perhaps the most widely recognized of all northern hemisphere mid-winter celebrations is Christmas or Christ’s Mass, a celebration of the birth of Christ. Activities surrounding this event are familiar to many and include family gatherings, special meals, decorations, religious ceremonies, songs, performing good deeds, and the exchanging of gifts. The celebration occurs on the Roman winter solstice, 25 December, after the solar calendar created by Julius Cesar replaced the earlier lunar calendar. Using our modern Gregorian calendar, 21 December marks the winter solstice in the northern hemisphere.
In the southern hemisphere, the winter solstice was celebrated by the Incas with the Festival of the Sun. Stone monuments at Machu Picchu still bear witness to this ancient religious ceremony, being high enough in the Andes to have escaped discovery and destruction by the Spanish Conquistadors.
At the South Pole, our mid-winter celebration included special meals, greetings of “Happy Mid-Winter”, and watching traditional South Pole mid-winter movies, such as Stanley Kubrick’s “The Shining.”
After spending a winter in Antarctica living in such an extreme, isolated environment deprived of many of the traditional comforts of home, the 21stof June and the austral winter solstice will forever be a very special day for me.