SUMMER TRIANGLE

During the heart of summer three bright stars make a large, noticeable triangle in the sky (Vega, Deneb, and Altair). This Summer Triangle can be seen even from the most light polluted skies. Although it makes a nice urban constellation, each star is really part of its own heavenly picture.

High up in the sky is bright, blue Vega. Vega is where the aliens from the movie Contact were calling from. Not too far away (only 25 light years), Vega is part of the constellation called Lyra the Harp. Lyra looks like a small parallelogram.

Down and to the left is dimmer star called Deneb. Deneb is a whopping 3,000 light years away - making it the farthest star you can see with the naked eye. This is the tail of the swan, the constellation Cygnus - and these stars actually look like a swan with a stretched out neck going to the right and wings up and down. Cygnus is also called the North Cross because, well, it looks like a cross jutting into the center of the Summer Triangle.

To the right is bright, white Altair. Altair is the head of the constellation Aquila, the Eagle. Although the Eagle might be tough to imagine from the stars, Altair is easy to find because it has two dimmer stars bracketing it.  And it's so bright because it's only 17 light years away.

Look for the Summer Triangle hight in the eastern sky after sunset - closer to overhead later at night.
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SUMMER SOLSTICE

Today, June 20 is the Summer Solstice which means that the Sun appears the farthest north for the year.  You know how the Earth is tilted 23.5 degrees?  Well, the northern hemisphere is tilted most directly at the Sun today and we're soaking up solar energy to the max. 

But we are we tilted 23.5 degrees to?  It's two factors - our daily rotation on our axis, and our year revolution around the Sun.  Our axis is tilted 23.5 degrees to the plane of our orbit - the path we take around the Sun.  So our entire Earth spins a little on our side as we orbit the Sun. 

BTW, the word solstice means, "Sun Standing Still."  Now that doesn't mean that the Sun stops for a second or two.  Our ancestors noticed that on a few days in the summer and a few days in winter that the Sun rose from the same spot in the northeast and set over the same spot in the northwest.  Other times of year, they could see the Sun rise and set in slightly different places each day.  But not on the solstices!  So it's the Sun's Path that stands still for several days, not the Sun.  Civilizations around the world  marked these special days with monuments that tried to capture those rising and setting sun rays like at Stonehenge, Serpent Mound, Fort Ancient, and Chaco Canyon.

Go check it yourself.  See where the Sun rises and sets over the next few days and you'll see what I mean.
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