Speaker: Dr. Ivan Ghezzi, Unidad Ejecutora Chankillo, Casma, Peru
This lecture is presented by The Pre-Columbian Society at the University of Pennsylvania Museum. It will be held on Saturday, November 8th 2025 from 1:30pm to 3pm. The event will be only on Zoom (Link Here).
Abstract:
“The Chankillo Solar Observatory in Casma, Peru, is a 2,300-year-old instrument designed for landscape timekeeping, capable of determining specific dates throughout most of the year with an error margin of just 1-2 days. While similar sites are used to mark key dates such as solstices and equinoxes, Chankillo operates daily at sunrise and sunset, making it a “complete horizon calendar.” The region surrounding Chankillo is characterized by significantly less cloud cover and thus better visibility than much of coastal Peru, which explains in part the title of “the cradle of pre-Inca astronomy.” Despite the wealth of prehistoric sites in the region, many of which represent millennia of monumental construction prior to Chankillo, these sites had not previously been systematically analyzed using modern archaeoastronomical methods. During 2024 and 2025 we have measured specific architectural features at several pre-Hispanic sites across the Casma, Sechín, and Nepeña valleys with the aim of uncovering evidence of the long process of experimentation, learning, design, and knowledge transmission that ultimately led to the creation of the Chankillo Solar Observatory. In this presentation, we share the results of our archaeoastronomical research, focusing on the use of plazas and platforms—specifically, axes of symmetry and diagonals—as representations of different “axes mundorum” within the pre-Hispanic worldview of the region (3500 BC – 200 BC).”