So long, Summer 2012. It started early, and gifted us with months of hot, sunny weather. While the rest of the country baked, few in Maine were complaining about the balmy breezes and steamy nights. Once we got acclimated to the waves of heat that began to arrive in May, our bones relaxed.

But, if we didn't like meteorological change, we wouldn't be living in Maine, the land of rapidly shifting air masses and sometimes very weird weather. So out with summer, and in with autumn!

"Come said the wind to
the leaves one day,
Come o're the meadows
and we will play.
Put on your dresses
scarlet and gold,
For summer is gone
and the days grow cold."
      -  A Children's Song of the 1880s

At 10:49 a.m., Sept. 22, Eastern Standard Time, Fall 2012 will officially be ushered in by the autumnal equinox, that celestial instance when day and night are of equal length (equinox, from Latin, means equal night). The autumnal equinox occurs when the sun's movement crosses the celestial equator moving from north to south.

From the website EarthSky: "Because Earth doesn’t orbit upright, but is instead tilted on its axis by 23-and-a-half degrees, earth’s northern and southern hemispheres trade places in receiving the sun’s light and warmth most directly. We have an equinox twice a year – spring and fall – when the tilt of the earth’s axis and earth’s orbit around the sun combine in such a way that the axis is inclined neither away from nor toward the sun."

The equinox is the great equalizer. It is the time, twice in a year, when just about everywhere on earth is privy to 12 hour of day and 12 hours of night. Now, the days will get shorter and shorter, until late December, when we will be putting our lights on at 3:30 p.m. and rising in the dark morning to greet the day. A far cry from those short, sweet nights of July, when the last glimpse of daylight was visible until 10 p.m. and the birds were signing at 4 a.m. -- if not all night long.

Here we go, though. Time to stack the wood, bank the house, pull sweaters out of the drawers, and harvest the garden. For many, it is the favorite time of year. One thing is certain: it won't last.