This March 19th at 10:30pm, spring will officially arrive in the northern hemisphere. The Sun will have set directly in the west, and will rise directly in the east the next morning. Day and night will be within a few minutes of being of equal length. The year’s two equinoxes, Vernal (spring) and Autumnal (fall) happen six months apart, marking the times when the Sun crosses the plane of our equator.
We have seasons because the Earth’s poles are tilted 23.44 degrees to the plane of our planet’s orbit. We didn’t start out that way.
All the planets formed from a spinning disk of rocks and stuff left over from our Sun’s formation. These leftovers just orbited around bumping into each other for a few million years, eventually gravitating together into some decent planet-sized rock piles. Still, every once in a while, a big unattached boulder would come along and give something else a whack, sending them spinning. In fact, the word on the street is that the Moon was formed from a chunk of the Earth knocked off by a particularly nasty body-check. It’s no surprise most of the planets spin a little off-centre; they grew up in a pretty rough and tumble neighbourhood.
What is under-appreciated about all this is that if the Earth were not tilted, we would experience only a single season with world-wide temperatures somewhere above freezing. That ‘above freezing’ part sounds good, but without that 23 degree tilt, it is unlikely that the game of hockey would have ever been invented. It is my personal theory that the excessive body contact in the game is also a throwback to the early days of planet formation.
Also, the astronomical symbol for the Sun is a circle with a dot in the middle, not unlike a hockey rink’s faceoff circles. Coincidence? As well, the rink is bisected into two equal parts by a line not unlike our equator. But, the clincher is that, come mid-February, just as you get all excited that winter’s end is near, you get hit by a blizzard and major disappointment, and then again, and again. February is the universe’s version of the Toronto Maple Leafs; Spring is obviously its way of apologizing.
The Sun will have set three and a half hours before the official time of the equinox, but luckily, as an equinox is nothing you can actually see, you won’t have missed anything. It will, however, make for a good night’s sleep knowing that you when you awaken, you can take in the first day of spring from your own back yard.
