Reachable Stars: Patterns in the Ethnoastronomy of Eastern North America

8. The Path through the Stars

The largest constellation in the night sky is the Milky Way. It is barely recognized as a constellation in the Greek tradition, but it is considered a major player in the drama of the sky by peoples in the New World (Freidel et al. 1993; Sullivan 1996; Urton 1981). The “Milky Way” is identi¤ed in the Old World’s astronomy, of course, but it is not thought of in the same way as the constellations that make pictures in the sky. That is probably because the others are made up of sets of bright stars, whereas the Milky Way is composed of thousands of dim stars that blend together in the eye to form the “milk.” Moreover, it is huge, spanning the visible celestial hemisphere on most nights. The dimness of most of the stars contributes to its being ignored today, because in the modern electri¤ed world the great constellation has become invisible in places affected by the urban lights. The Milky Way is different from the other constellations in the scienti¤c understanding , also. While other galaxies can be seen, they appear as fuzzy stars. The Milky Way is closest to earth, however, because it is the local galaxy, the one within which the solar system resides. In the scienti¤c worldview, this galaxy can be seen by humans only by looking from earth’s position close to the edge. The view toward the center of our own galaxy, which is similar to the one shown in Figure 8.1, shows it as a streak of intense starlight across the night sky. Even though the galaxy is ¤xed in relation to the customary constellations, because of a combination of complicated movements by the earth in relation to the galaxy, the Milky Way appears to whirl in the night sky. For people who are not accustomed to thinking of the Milky Way as an actor in the celestial drama, it takes some acclimatization to become comfortable with its counterintuitive motion. 8 The Path through the Stars Figure 8.2 shows three images of the Milky Way’s movement over the course of a single night. The viewing location and time are arbitrary. St. Louis has been selected because it is a central spot in the Eastern Woodlands and Plains and because it is near Cahokia, the largest prehistoric center of Native America. The date is a.d. 1500, although Cahokia’s glory was already only a memory by that time. To look at these three “snapshots” of the Milky Way during the night of October 1–2, imagine yourself lying on your back on the ground with your head pointing to the north. Note that from this position east is on the left and west is on the right. The sky’s movement is thus from left to right. When the light of the sun fades in the west and the stars become visible in the night sky, the Milky Way is revealed as a northeast-southwest band with a distinctive fork directly above. Six hours later the band stretches from east to west, with the fork to the right. As dawn’s light begins to obscure the stars, the Milky Way is a northnorthwest to south-southeast band, with the fork over the northern horizon. As the celestial vault shifts through the solar year, the Milky Way goes with it. By April 2 the dusk and dawn positions of the Milky Way are roughly reversed from the October ones. The cycle of the Milky Way is regular, even though it is Figure 8.1. A galaxy from outside (photograph from NASA, ESA, and the Hubble Heritage Team [STScI/AURA]: “Spiral Galaxy NGC 3949: A Galaxy Similar to the Milky Way [STScI-2004-25]”). 202 chapter 8 Figure 8.2. Earth’s galaxy from inside (image produced by Voyager II software for October 1–2, a.d. 1500, as seen from St. Louis at [a] 5:50 p.m. [dusk], [b] 11:30 p.m., and [c] 5:50 a.m. [dawn]). impossible to describe in words and dif¤cult to grasp from viewing static images. To appreciate the Milky Way’s unique movement, the viewer needs to view the sky throughout a calendar year. The best method of all, however, is to watch the annual cycle on a computerized planetarium display, with the time greatly increased so that the great swings of the galactic disk...