The most magical time of the year

Solar noon marked over the course of a year. The figure-eight pattern is called an Analemma

Believe me, if you grew up in Texas, where summer heat tops the century mark for weeks on end and even the morning lows offer little relief, you’d feel December was pretty damn magical. This month dawn and dusk stretch out, as the sun marches steadily to the Winter Solstice. The solstice was  a magical time for our ancient ancestors, too, the sun looked like it was going away and they were afraid it might keep going! So after the shortest day of the year, anywhere from Dec 20 to 23 on our calendar, a returning sun was cause for celebration indeed. You might think the shortest day of the year would have the latest sunrise and earliest sunset. But here in Texas and throughout the temperate section of the northern hemisphere, it actually doesn’t work out that way.

Here in North America, if you mark the highest point the sun reaches in the sky each day, called Solar Noon, and put them all together, it makes a slumped-over squashed figure-eight like the one above called an Analemma. If you look at the bottom, the Winter Solstice happens at the inflection point marked 21.12. But thanks to the earth’s axial tilt and other factors, solar noon happens a little later each day as Winter approaches, and that means the earliest sunset has already happened before the solstice is reached. If you looked at the image you can somewhat visualize this, when the sun is just above the Solstice it sets a little earlier and when it’s just below the Solstice point it rises a bit later. The earliest sunset is happening this whole week in Texas and the latest sunrises will occur on January 10 and 11, 2012.

The shortest day happens in between those two times, and that of course of the Winter Solstice itself which is scheduled for 5:30AM UTC on Thursday, Dec 21. Unless of course the sun really decides this time not to return and just keeps on going …