Autumnal Equinox

We've just passed out of summer and into fall. It doesn't feel particularly different this morning but I guess my internal magnetism ought to be telling me it's time to move south. We've had a light shore-bird migration this fall at Rankin Bottoms and it's too early for geese. I have had only one time, when over near Greeneville, Tenn., seeing a long vee of geese and they were against the late sun. It was quite a sight. The hawk migration through Mendota, Va., continues. Why this isn't some kind of exodus for bird watchers, I don't know. The fall migration for warblers is just beginning. I suspect us humans will start migrating to the sales for fall and winter clothes and attic insulation.

In our Astronomy class, last night, the evening of equinox, we used the celestial sphere to map out a few stars and use Right Ascension and Declination coordinates. (And one fantastic full moon over campus.) No doubt migrant birds and winter-hibernating mammals already know their RA and Dec-degrees. When we visited Cahokia Mounds State Park in Illinois many years ago I was surprised to learn they had uncovered a sun-calendar of their own. I think since then I've tried to notice where the sun location at the beginning of the four seasons.

When I went to put up the flag at just about eight o'clock the sun was just peeking over the Walls' house across the street. The sun comes through my front door, in through the bathroom, and out the bathroom window in a line. The summer solstice sun pours in the north bedroom window and out the west window in the bedroom. Quite a change. It's six months until the sun comes back up at eight o'clock over the Walls roof again.

The local weather has been extra warm but not record setting. That'll change overnight almost and then the windows come down and short-sleeve shirts trade closet space with the long-sleeved shirts.

The astronomy of the picture website (http://apod.nasa.gov/apod/) --a must for all sky watchers-- explains that equinox translates into "equal night. "
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