Astronomy was a fairly developed science for the Incas as it was closely interlinked with their religion and their ritualistic practices.

Many of the structures in their historical sites were also created simply for star gazing or to map out the movements of the sun and moon such as the Temple of the Sun at Ollantaytambo.

For the Incas, the stars were powerful indicators and symbols. Some constellations were meaningful because they related to the life and power of certain animals and also acted to protect them from the other forces.

The belief was that Viracocha (creator of all things) wanted the stars to protect certain sacred animals and spirits which is why the Inca had corresponding constellations for each animal. The constellation named Pleiades was understood to affect the behavior and health of the animals which is why Inca shamans often made sacrifices to it.

Furthermore, the stars were considered a kind of Huaca (revered spirit or being emerging as a naturally occurring object or phenomenon) which is why they were necessary in worship and were often used to reveal the correct times for certain rituals.

Two Forms Of Inca Constellations

For the Incas, the stars were almost a mirroring of their life on Earth, with many of the same animals and items represented. They mainly believed in two kinds of constellations with regard to their religion and spirituality.

The first kind were collections of stars which were devoid of meaning with the dots coming together to form everyday shapes such as the faces of human beings.

The second kind of constellation, however, was the stars which could not be seen by the naked eye but created dark patches in the night sky specifically in the Milky Way and were considered alive and full of wisdom.

When compared with most civilizations, Incas were perhaps the only race that saw meaning in stars which were not visible. The Incas thought of the Milky Way as a large life-giving river which possessed sacred animals.

The Application Of Astronomy To Agriculture

The crop cycle was no doubt one of the most important things for the Incas and the messages and positioning of the stars played a pivotal role in guiding the farmers the year round.

The stars were studied to decide the best times for harvesting and sowing the crops mainly corn and they also pointed towards the changes in the season and the time of the solstice which was necessary for a lot of Inca rituals.

The Inca farmers would hike to the top of the Andes Mountains to observe the stars each year at the end of June (which was their winter solstice according to their calendar even though today June is synonymous with summer).

They charted the movement of the Pleiades in particular, which is a collection of seven stars in the galaxy and the clearer these stars were, the more certain they felt that the coming year would bring steady rainfall which would benefit the crops.

Their growing season went from October into May and if the constellation appeared murky or unclear, they knew they had to make sacrifices to the gods in order to ensure a healthy cropping season.

Mach’acuay- The Serpent Constellation

Snakes were a sacred animal for the Incas even though they were not really an indigenous creature for the areas which the Inca inhabited since they preferred to live in the mountains and hills.

Machu Picchu is an excellent example of them preferring higher altitudes and the reason for this could very well be the myth of the flood (a natural occurrence at the time of their ancestors that wiped away all life) which kept them wary of living on level plains.

The serpent was given a variety of interpretations and the Incas did not consider it synonymous with evil as many older cultures typically did, but instead believed it possessed acumen for telling the future and the correct outcome of difficult decisions.

Even the rainbows were considered serpents and called ‘Amarus’. The serpent constellation for the Incas held one main purpose which was to provide nourishment and protection for the snakes on the land so they could live without being hunted and multiply endlessly by giving birth.

A thought-provoking fact for people visiting the Inca region for a meditation retreat is that the Incas were able to accurately relate the movements of the constellation to the activity of real-life snakes in the valley and plains.  Even today the constellation emerges most clearly in August to disappear as February approaches and snakes are most efficacious in the same season.

Hanp’atu- The Toad Constellation

The toad was used for the purposes of divination by the Incas who thought that the croaking of the toads would signal a good harvest and plenty of rain. They also considered the natural sounds of the animal to be the harbinger of goodwill.

Same as the snakes, the frogs are generally more active during the season of the rains which is when their constellation also appears in the sky. The Toad constellation was also used to pinpoint the most ideal time for the community to start planting their crops.

Urcuchillay- The Llama Constellation

This was perhaps the most crucial constellation to the Incas as the animal was symbolic for godly sacrifice, an abundance of food and the use of animals for carrying heavy burdens.

The two stars namely Beta Centauri and Alpha act as the llama’s eyes and the constellation nearly always shows two llamas clearly (a mother and her child).

Llamas were sacrificed by the Incas too although only at specific times of the year usually solstices and equinoxes.

Atoq- The Fox Constellation

This constellation also mirrors the cycles of foxes on Earth as it appears in December which is a birthing season for the animal.

The fox is also an instinctual hunter of the Vicuna in the Andean region and the Incas were fascinated by it since the reversal happens very often and the hunter becomes the hunted (a herd of Vicunas can kill a fox very easily).


The Incas were probably not the first civilization to come up with the concept of everything in the universe being connected but it was a salient belief for them nonetheless.

They had faith in a synergy amongst the naturally occurring elements of their surrounding physical environment. For them nothing happened without a pre-decided and cosmic reason. For the Incas the stars in the sky were a parallel running reel of the events and beings present down on Earth.

Many rural Andean settlements still practice some of the same beliefs with regard to the stars and tourists on a Peru holiday can witness firsthand the magic of stargazing that so captivated the Incas centuries ago.

Macho Picchu in particular has been concluded by historians to have been a significant astronomical observatory and also an auspicious ceremonial site for rituals related to the constellations.

The height of Machu Picchu could easily have been a major component in what made it ideal for observing the patterns of the stars and many smaller structures inside it seem to suggest they were used for this purpose.