The Big Dipper is high in the evening sky now, nearly overhead. The pattern of stars we call the Big Dipper is usually one of the first star patterns we learn. It is easy to see because it is quite large, it is always above the horizon at our latitude, and all of the stars are about the same brightness -- all but one are second magnitude stars. This easily recognized pattern of stars is officially an asterism; it is part of the region of the sky called the constellation of Ursa Major, the Great Bear. It is possible, with some imagination, to find a pattern that might represent a bear by using stars to the west of and below the dipper, but the stars which make up the remainder of the bear are considerably fainter than the stars in the Big Dipper. And the handle of the dipper represents an awfully long tail for a bear.

        Three of the stars in the Big Dipper have their names printed on the chart for this month's sky -- Dubhe, Mizar, and Alcor. These last two are really located at the same place in the handle, with Alcor appearing as a faint companion to Mizar. Mizar and Alcor are not really a binary pair in the sense of one orbiting the other; rather they just happen to appear along about the same line of sight. Mizar, in fact, has a companion gravitationally bound to it that can be seen quite easily with a modest telescope, and, in 1650, was the first star to be noticed as a double with a telescope.

        The names for most of the stars in the Big Dipper are Arabic. Dubhe is from the Arabic for "the back of the bear." The remaining stars, continuing around the bowl and then out the handle of the dipper, are Merak (the loin of the bear), Phecda (the thigh), Megrez (the root of the tail), Alioth (origin uncertain, but perhaps the "fat tail" of an animal), Mizar (a girdle or waist-cloth) and Alcor (origin unknown, but maybe "rider"), and Alkaid or Benatnasch (from Ka'id Banat al Na'ash, Chief of the Mourners). None of these names for the stars in the handle of the dipper is associated with a bear, so it is obvious that even the Arabs had some difficulty with such a long tail for a bear. The American Indians, who surprisingly saw the same pattern, knew very well that a bear's tail is short, and ascribed the stars in the handle of the dipper to three Indian hunters who were chasing the bear around the sky. The faint star Alcor was called the cooking pot by them, carried by the middle hunter for stewing the bear when it was finally taken. One tale suggests that Jupiter grasped the bear by the tail while putting it into the sky in order to avoid being bitten, and the great weight of the bear stretched its tail.

        Some readers of this essay may have seen sketches of the shape of the Big Dipper as it will appear 10,000 or 100,000 years in the future. It certainly will not look like a dipper, but only the stars Dubhe, at the tip of the bowl, and Benatnasch, at the end of the handle, will have shifted from the pattern of the dipper. The remaining five stars (six, counting Alcor) will still have the same locations relative to one another. These six stars are not totally unrelated as are the stars in most star patterns that our species has devised as we seek to find some order in random patterns. They are part of a cluster of stars called the "Ursa Major Moving Cluster." There are ten other certain members of this cluster and one whose membership is uncertain. The uncertain member is the brightest star in Corona Borealis. Of the remaining ten, one is in Draco, one is in Leo Minor (a small constellation between Ursa Major and Leo not shown on this month's chart), and the others are all in Ursa Major itself. This is the closest cluster of stars to the Sun, similar to the Pleiades in Taurus but with many fewer stars. Its shape is an ellipsoid having a length of 30 light years and a width of 18 light years with a center about 75 light years away, and it is moving toward the constellation Sagittarius.