Incan astronomy

The Inca were very much aware of celestial cycles such as the summer and winter solstice, and kept a careful track of the passage of the sun, moon and stars. The Inca had both a solar and lunar calendar, which they used to time key celebrations and rituals, and they also followed the cycles of other key celestial objects such as Venus and Mars.

Solstices were measured by making observations from points in Cuzco to stone pillars on the horizon. From Machu Picchu, the sun rises directly above Intipunku, the Sun Gate, during the winter solstice, and in the Sun Temple a window is oriented exactly to the azimuth of the Pleiades. The summer and winter solstices were extremely important times of year for the Incas, and were marked wit huge festivals.

Constellations

The Inca followed two different types of constellation. As well as seeing stellar objects as important, they also observed structures within the Milky Way (or Mayu, the Celestial River) defined by the dark patches of dust between us and the dense backdrop of stars.

In the night sky, the Inca people saw the stars as being spiritual counterparts to every kind of animal. For example, Chuquichinchay, the jaguar star, was important to people living in or travelling through the jungle, who would make sacrifices to it. Stellar constellations of importance were the Pleiades, which they called the Colca "Store House" and said the stars of the animals came from and returned to. The Southern Cross was also a very important symbol in Incan cosmology.

The "dark cloud" or "dark star" constellations of the Inca also take the forms of animals. Within the Celestial River, these shapes were known to the Inca as the Llama, the Toad, the Snake and more, and like the stellar constellations were revered by those who dealt with, or relied upon, these animals. The Milky Way itself was also important, thought to be a mirror image of the great Vilcanota River that runs across Peru, and the Chakana (Andean Cross) may have been derived from the symbology of the cross made when the Milky Way aligns with this terrestial river, bringing together heaven and earth: the Quechua for Chakana is derived from the verb chakay, "to cross" or "to crossover".

Next - The Chakana