The Dark Astronomy of the Inca

​One of the most fascinating things I learned about Inca culture traveling through the former heart of their empire, Peru, has to do with their astronomy.

Every ancient civilization looked to the night sky and the glimmering fires in it for inspiration and for guidance. Indeed, a serious argument has been made that post-industrial humans, unable to discern most of the stars in the sky from most of the places where we live due to light pollution, are fundamentally losing the cosmic perspective that our ancestors had for millennia. We moderns are liable to forget our place in the universe. But that story will have to wait for a later date.

The constellations that Western peoples saw when they looked up are familiar to us as a matter of popular culture: Aquarius, Leo, Virgo, Pisces, Gemini, Scorpio, Orion, etc. Even today many of us obsessively (and entirely irrationally) check our horoscopes on the basis of that view of the stars. Other cultures — India, Babylon, Persia, China — looked up and connected different dots and named different constellations. But usually they were at least connecting the bright dots as well.

The Inca, on the other hand, looked up and focused on the dark spaces in between.

Image of Milky Way depicting the Incan constellations. Source: Koricancha Temple in Cusco, Peru.

When they looked up at the Milky Way, they saw a celestial river that they called Mayu that ultimate provided all the water on earth and corresponded to the nurturing Urubamba, the river flowing through the Sacred Valley just outside today’s Cusco, Peru, the puma-shaped ancient capital of the Inca. And the Inca noticed that stretches of darkness marked the silver band as surely as the stars shone.

They called them “yana phuyu,” meaning “black clouds.” And they identified them with animals stopping by the great river of life to drink their fill. Not surprisingly, the animals were the ones with which the Inca were familiar: The Yacana consists of a mother llama and her baby, and the two eyes of the mother are Alpha and Beta Centauri in Western astronomy, the former being the nearest star to our sun. Then there are the Serpent, the Toad, the Partridge, the Fox, and Micheq the Shepherd, likely a female figure, overlooking the menagerie. Dark constellations all.

Until I visited Peru, it never occurred to me that an ancient civilization would learn to focus on the areas of darkness amongst the stars. But of course they did, of course someone did. Music is the silence between the notes. And our modern physicists and astronomers now understand that most of the universe actually consists of dark matter and dark energy not only invisible to our eyes but to nearly all of our means of observation.