In the summertime, when the skies are clear and dark, it's possible to see a galaxy on display. This galaxy is called the Milky Way, and it is our home, a giant star city, one of hundreds of billions in the vast emptiness of the universe. The Milky Way is shaped like a spiral disc or pinwheel, some hundred thousand light years or so across. One light year equals six trillion miles, which means our galaxy is over six hundred thousand trillion miles in diameter - big! There are perhaps two hundred billion stars in the Milky Way, and our sun is but one solitary star about two-thirds of the way out from galactic center. Go out tonight and look for the arm of the Milky Way - a faint hazy band of light arching across the sky. In the late evening, around 10 PM, it stretches from due south – the constellations Scorpius and Sagittarius - toward the zenith – the three stars of the summer triangle, and then down to the constellation Cassiopeia in the north.