Archeoastronomy

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The study of nonwritten evidence for astronomy practices and knowledge in past civilizations and societies. Artifacts of interest to the archeoastronomer include megalithic remains in northwestern Europe, especially stone circles such as Stonehenge, and rock art, depicting events such as supernovae, by Native Americans and Australian Aborigines.

The interdisciplinary study that attempts to determine how much astronomy prehistoric people knew and how it influenced their lives. It involves multiple disciplines: astronomy to chart the heavens, archeology to probe the cultural context, engineering to survey sites, and ethnology to provide clues to the cultural past. Archeoastronomy has prompted valuable insights into the astronomy of the past, even to revolutionizing some models of prehistoric cultures. It has been suggested that archeoastronomy and its loose family of disciplines should be subsumed under a broader study, cultural astronomy. The reason to do cultural astronomy is that the sky can perform a special role in the scheme of cultural systems. The sky then serves as a cultural resource of many uses. The cultural context is the key to understanding the findings of archeoastronomers. Finding astronomical orientations at sites is easy; interpreting these as intentional alignments is hard. It is necessary to consider what their purpose might be (to keep a seasonal calendar? to regulate sacred time? both or neither?). The great danger is the imposition of modern astronomy and culture upon an alien culture of the past. See also Archeoastronomy; Astronomy.

Every prehistoric culture appears to have developed its own astronomy. The traditional navigators of Oceania needed to memorize guide stars and to employ them as the bearing markers for island-to-island travel over thousands of kilometers of water. The Carib people of northern South American developed a calendar that relied on the positions of stars relative to each other and to the Sun at times of rising and setting. A bone from the shores of Lake Edward, Zaire and Uganda, may have markings of a lunar calendar, tallied at a time over 8000 years ago, perhaps used to forecast marine activity or the weather; a focus on the Moon continues in Africa today. Chinese astronomical records cut into bones and shells may have begun as early as the twelfth century B.C., well before the Babylonians incised their earliest records on clay.

By the time the Spanish invaded Mesoamerica and South America, the use of astronomy went well beyond complex systems of cycles and calendars. For instance, in some Mayan cities knowledge of the cycles of Venus timed the onset of warfare. In others, key political events incorporated the summer solstice and perhaps conjunctions of Jupiter and Saturn. Ancient Inca city planning and politics embodied astronomy, such as the ceque system of radial lines from the Temple of the Sun in the valley of Cuzco. These lines mark the directions to sacred places as well as to specific astronomical phenomena. The ceque system had a calendric manifestation in knotted cords that tallied the days of the agricultural year.

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