The Astronomy of Peruvian Huacas

Farmers in drought-prone regions of Andean South America have historically made observations of changes in the apparent brightness of stars in the Pleiades around the time of the southern winter solstice in order to forecast interannual variations in summer rainfall and in autumn harvests. They moderate the effect of reduced rainfall by adjusting the planting dates of potatoes, their most important crop. Here we use data on cloud cover and water vapour from satellite imagery, agronomic data from the Andean altiplano and an index of El Nino variability to analyse this forecasting method. We find that poor visibility of the Pleiades in June-caused by an increase in subvisual high cirrus clouds-is indicative of an El Nino year, which is usually linked to reduced rainfall during the growing season several months later. Our results suggest that this centuries-old method of seasonal rainfall forecasting may be based on a simple indicator of El Nino variability.

Ethnohistoric sources suggest that the indigenous inhabitants of Andean South America saw both people and things as animated or enlivened by a common vital force ( camaquen ). In approaching the subject of camaquen archaeologically, I attempt to place objects and their materiality at the analytical centre, rather than the normally privileged ethnohistoric or ethnographic data, in order to see what new insights into the nature of Pre-Columbian ontologies might be gained from ‘thinking through things’. In this, I follow recent theories premised on the idea that the traditional segregation of concepts and things may hinder understanding of alternative worlds. The study focuses specifically on the arrangements, relationality and referentiality between and among objects found in sacred and offering contexts dating to the Inca period.