1 A Brief History of Eclipse Observations in China David W Pankenier, Lehigh University Observational reports of many kinds compiled by successive Chinese dynasties have survived to the present time. These constitute the world’s most comprehensive and continuous collection of such records and are an invaluable resource in historical research. Recent compilations including solar and lunar eclipses, sunspots, auroras, meteor showers, comets, planetary conjunctions, novas and supernovas run into the thousands of such records. But astronomical observation in China can be documented long before the historical period began in the Bronze Age (second millennium BCE). Astronomically inspired motifs already began to appear early in the Chinese Neolithic. While they provide evidence of significant interest in the sky and heavenly bodies, one cannot infer from them that actual “observation” was taking place. Clear evidence does, however, appear about the same time in the cardinal orientation of burials, house foundations, sacrificial altars, and so on, that display obvious axial alignment. This could only have been accomplished by systematically observing and marking the rising and setting points of the Sun on the horizon. A recent major discovery is Taosi, a late-Neolithic site containing the ruins of at least four pre-dynastic cities that successively occupied the place from about 2500 to1900 BCE. Taosi elites engaged in ritualized astronomy and systematic timekeeping by solar observation. Discovered in 2003 abutting the southeast wall of Taosi’s large Middle Period city are three concentric pounded-earth structures, in the shape of a three-tier altar platform. The top tier is a semi-circular terrace. Adjacent to the terrace is an elite burial ground used for sacrificial offerings. On it a curved pounded-earth wall facing south—southeast, surviving traces of its base still perforated by twelve regularly spaced grooves. Analysis of these grooves indicates that they are the remains of more or less uniformly shaped earthen pillars. Archaeologists realized that the platform from about 2100 BCE might have been used to observe the rising Sun. The range in azimuth along the horizon defined by the platform pillars matches the arc traced by the Sun as it moves along the horizon between the solstitial extremes.