Happy Autumnal Equinox 2016!

Today is the last day of astronomical summer and the first day of astronomical fall.  Treehugger gives the exact time of the transition today in 12 things to know about the 2016 autumnal equinox.

Well hello, fall.

Even though it happens year after year, the arrival of autumn is always a little surprising. Almost as if on a switch, one day late in the summer you feel it – a subtle crispness in the air. And before you know it, it’s pumpkin-spice-everything everywhere. We are suddenly swathed in sweaters and wearing boots and bombarded by shades of orange, often even before the thermometer warrants it. After slogging through a long hot August, it's exciting.

We can thank the autumnal equinox for this shift from sultry summer to cozy fall. And while most of us are aware of when the first day of autumn lands on the calendar, there’s more to the equinox than meets the eye. Consider the following.

1. This year, the autumnal equinox arrives precisely at 10:21 a.m. (EDT) on Thursday, September 22. Unlike an event like New Year’s midnight that follows the clock around the time zones, equinoxes happen at the same moment everywhere.

Eleven more facts at the link in the headline.  You can read them, or you can watch this video from National Geographic.

Just twice a year, day and night fall into perfect balance. Some claim that astronomical phenomenon, called equinox, inspires ancient structures to reveal hidden secrets.

Or you can do both.  Either way, happy equinox!