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Hopping the Heavens

Follow the Big Dipper

The sun sets a little before 8:00 this week, with full darkness coming almost an hour later. By that time, the great bear Ursa Major is almost directly overhead. The third-largest constellation, Ursa Major has been seen as a great she-bear by ancient peoples from Greece to India, Babylon to North America. In the modern age, when the few bears most of us see are captive in zoos or performing in circuses, we are more familiar with the seven stars of the bruin’s hind-quarters, a grouping that forms the Big Dipper.
    While the Big Dipper is not a constellation in its own right but rather an asterism, it is perhaps the most recognized shape in the Northern Hemisphere. For us along Chesapeake Bay, and anyone else above 40 degrees latitude north, the Big Dipper is circumpolar, meaning it is visible year-round. Which makes it an excellent aid to navigate the night sky.
    Look to the bowl of the Dipper and for the two pointer stars of its outer edge. Continue a line through these stars to the north and you come to the North Star Polaris, amid the Little Dipper, properly named Ursa Minor. As the little bear is also circumpolar, this is a nifty trick for quickly getting your bearings when gazing at the night sky.
    Back to the Big Dipper, follow the stars of its arcing handle to Arcturus. This orange-red star, the fourth-brightest in the sky, is part of the constellation Boötes and was known as the Bear Keeper, herding the big and little bears through the heavens.
    From Arcturus, spike down to Spica, the shaft of wheat in the hand of the reclining goddess Virgo. While a dim constellation, Virgo is at the center of one of the densest sections of the universe, the Realm of the Galaxies. A relatively modest 65 light years away, it is made up of thousands and thousands of galaxies, more than 100 visible to the unaided eye.