Book excerpt: Chaco Astronomy: An Ancient American Cosmology contains the remarkable findings of the past three decades of scientific and cultural investigations into the astronomical practices of the ancestral Puebloans -- people who built massive expressions of a remarkable world-view in the American Southwest. Compiled by Anna Sofaer and her Solstice Project team of geographers, astronomers, archaeologists, and Native scholars, the book includes nine compelling and detailed chapters, with photographs, charts, diagrams, appendices.