As we move into the summer, our gaze shifts from our neighbors in the Local Cluster towards our galactic plane. The Milky Way rises higher and higher into the night. Unfortunately, the delicate hazy band is amongst the first casualties of an increasingly light polluted society. Thanks to telescopes and modern astronomy, we now know that the haze is a collection of stars and interstellar dust along our galactic plane that our eyes cannot resolve. To some astronomers, it may even be a nuisance, garnering the ominous sounding title of the zone of avoidance, for all that light and dust prevents astronomers from making observations outside of our galaxy in the optical wavelengths. However, for ancient societies, the Milky Way was an enigma – it looked nothing like the rest of the night sky, with its faint fog-like appearance interspersed with dark patches. And as is uniquely human, our ancestors told stories of how the Milky Way came to be. Some of these tales we remember, others are lost to the ravages of time.
Our modern usage of the word galaxy derives from the Milky Way. The ancient Greeks called it Galaxias Kuklos (or sometimes Kuklos Galaxias) – the Milky Circle or the Circle of Milk. There are various myths as to the origins of the name, but most revolve around Zeus tricking Hera into feeding an infant Heracles. This naming tradition is something the Romans continued as well – Cicero also referred to it as the Lacteus Orbis, the Milky Circle/Orb. But not too long after him, things seem to have changed. Ovid was a Roman poet, born around the time Cicero passed. I do not know if he was the first to coin the term, but in the first book of Metamorphoses, Jupiter (Zeus) convenes a meeting of the Gods, and they travel along the Via Lactea, the Milky Way.
While the Greeks and Romans may have seen a path or a circle, in many East Asian cultures, the Milky Way is a celestial river. The Chinese call it Tian He, which translates into River of the Heavens. Along the path of the Milky Way lie three bright stars that form the Summer Triangle – Deneb in Cygnus, Altair in Aquila, and Vega in Lyra. Vega and Altair are two lovers perpetually separated by roaring eddies of starlight and dust. But each year on the seventh day of the seventh month, the river becomes shallow enough for these star-crossed lovers to meet, tracing a path over the tail of the swan, Deneb. The Japanese call the festival Tanabata, the Chinese Qi Xi.
The view of the Milky Way as a river is a common one across many cultures. To many of our ancestors, the celestial sphere mirrors our earthly existence. But whereas our lives are fraught with mutability, the night skies are consistent and predictable. The Karuna people are indigenous Australians living in Southern Australia, near where modern-day Adelaide resides. They too viewed the Milky Way as a river, the Wodli Parri (literally Hut River) where the gods hunted and fished. In what is a happy coincidence, or maybe an example of Jung’s collective unconscious, they describe the constellation we know as Orion as a hunter or a group of hunters prowling along the shores of the river.
The Milky Way is different from everything else about our night sky, and in the era before the telescope, it is not surprising that it caught the attention of humanity. One can easily imagine a glowing river interrupted by rocks and other obstacles in the night sky. The dark patches, which we now know as gas obscuring the stars, form dark nebula. We have names for some of the more prominent dark spots – the Coal Sack, the Great Rift. Unlike a river though, the Milky Way does not change over the course of a human lifetime. The Incas took it a step further, to them the Milky Way held within its shores a myriad of constellations. It is this interplay between the light and dark that drove their myths. The luminous portions were inanimate objects, with the dark nebula forming various animals. It is not just the consistent appearance of light they observed, but the consistent darkness as well; both were intimately connected.
And with that far too cursory overview of how some cultures looked at the Milky Way, we circle back to the beginning. The Navajo called the Milky Way Yikáísdáhá, or that which awaits the dawn. To understand why it is called this, remember that the position of the Milky Way drifts across the night sky depending on the season. From the Navajo Nation, located in the northeast of Arizona, there is one period in the year where the Milky Way appears to circle the entire pre-dawn horizon – January. For the Navajo, Yikáísdáhá was not just a name or location in the sky; it had temporal significance. In a volatile, capricious pre-modern world, the clock-like consistency of the celestial sphere formed an anchor by which our ancestors told their legends and planned their lives.
Additional Reading:
Sharing the Skies: Navajo Astronomy
https://amzn.to/2K28x5h