Saturday, September 24, 2011

Autumn…the REAL story

Did you ever wonder why leaves changed color in the autumn?  Now, if you listen to scientists or arborists or anyone who took seventh grade science, you might think that the reason is because the trees stop creating chlorophyll in response to the shortening days (see the last post to see why the days are getting shorter) as they prepare to go dormant in anticipation of a long cold winter.

But you, my dear friend, are about to know better!  The real reason why the leaves on trees change color is because the hunters finally caught the bear!

Lemme 'splain.

If you look low in the northern sky tonight (at about 9 or so) you will see the Big Dipper; three stars make up it's handle, four stars make up it's scoop.  The Big Dipper by itself is not a constellation, it is an asterism, which is a recognizable pattern of stars that is not a constellation.  The Big Dipper is part Ursa Major, the Great Bear––one out of 88 modern constellations.

The three stars that make the triangular head of the Great Bear are right in front of the Big Dipper's scoop, which itself is the bear's tuckus.  Below the head of the bear are three stars that make a slim isosceles triangle, this is the bears front leg; it's back leg is made by a similar triangle below the Big Dipper's scoop.  In many locations right now (including mine) part or all of the Great Bear's legs will be at or below the horizon.

Many constellations today are named after figures in Greek mythology and Ursa Major is no exception; but the Ancient Greeks weren't the only ones who saw a bear up in that part of the sky.  The Iroquois nation, which lived in what is now New York State, also saw a bear in the sky, but this bear was being chased by three hunters (the three stars in the Big Dipper's handle).  To evade it's pursuers, the bear leapt into the sky, but these were no run-of-the-mill hunters; they jumped right into the sky and continued their chase.  Throughout the end of winter and into the spring they chased the bear as it climbed higher and higher into the sky.

By the way, Ursa Major gets higher and higher in the sky in winter and spring, reaching it's highest point in April when, at 9 PM, it is completely upside down.

During the summer, the bear started to run back down to the Earth, but it was getting tired and, as summer turned to fall, one of the hunters finally managed to hit the bear with his spear––and the Great Bear bled.

Its blood came out of the sky and stained all the leaves on the trees.

And that is why the leaves change color in the autumn.

Not only is that a neat story to tell, it's also a handy way to remember where the Great Bear and Big Dipper will be at 9 PM in the autumn––low in the northern sky.

Have fun looking up!

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