The night sky, a World Heritage Site

One night more than 20,000 years ago, under an abysmal darkness, Otzi contemplates the starry sky at the end of spring. His mind as a Cro-Magnon man is incapable of providing a rational explanation for this cosmic vision, so he limits himself to enjoying it and fabling imagining stories. Over time, however, it will learn to recognize patterns, to notice periodic signals that appear throughout the year, allowing the first humans to predict events important for their survival. That millennial night, Otzi went to bed in his hut, understanding that the appearance in the night sky of that string of stars shaped like a scorpion's tail, just like the previous year, heralded the beginning of summer and good weather, the days would have more light, the ripening of wild fruits and the arrival of herds of deer to the meadows. Otzi unwittingly began to measure time with the stars. The night sky was our first calendar.

There are no reliable data, but it is not unreasonable to venture that the contemplation of the night sky began with the first modern humans, almost 70,000 years ago. Looking at the night sky in search of the meaning of existence is a hallmark of our condition as a species, of our humanity. From the Stone Age to the Space Age, we have contemplated the stars and have been enchanted by their majesty and beauty. This shared fascination with all human beings, from all peoples and periods of history, has helped to shape us as a civilization and as individuals.

To begin with, Heaven was, without a doubt, our first storybook. The small family clans of the Paleolithic era, sitting around the fire, contemplated the immensity of the cosmos and began to build legends and myths, projecting their daily avatars, hunting adventures and first spiritual abstractions to the stars. The verbal transmission of these stories helped to perfect language and was the germ of the first magical-religious cults.

This attraction to turn the sky vault into the genesis of stories continued to be cultivated with enjoyment in the following millennia. The Eastern peoples, the Sumerians, the Egyptians and, especially ancient Greece, turned to the stars a rich and complex mythology of heroes and gods that revealed the most diverse conditions and attributes of the human species: love and hate, revenge and courage, power, avarice and resentment, in short, death and life...

But the importance of the night sky doesn't end here. The stars were also our first map, our first compass, our first nautical chart. More than a thousand years ago, the Phoenician merchants who crossed the Mediterranean from Tyre to Gadir had their most faithful guides in the stars. The identification of constellations and the polar star allowed them to orient themselves and travel in the open sea, which enabled the expansion of trade and the establishment of the first colonies in the south of the peninsula, or in other words, of our first cities.

We still have one more milestone to tell about the importance of the night sky, perhaps the most important. More than 2,500 years ago, somewhere in Asia Minor, the father of European philosophy, Thales of Miletus, one of the seven wise men of Ancient Greece, after months of mathematical calculations, managed to predict the solar eclipse that occurred on May 28, 585 BC. The night sky was also our cosmic blackboard for the first laws of celestial mechanics, so many authors agree that the night sky was the germ of physical sciences and analytical geometry.

The human species would not be understood without the stars. The night sky was our first storybook, our first calendar, our first map, and the cosmic stage on which humans developed science and abstract thinking.

However, this ancient, intangible and intangible heritage is in serious danger as a result of light pollution, the set of radio emissions that originate from the outdoor lighting of towns and cities. As a result of this phenomenon, millions of people cannot enjoy the stars in the cities or towns where they live. Persevering in more efficient public and private lighting systems that illuminate the ground and not the sky will be a good way to combat this type of physical pollution, as reflected by the great Van Gogh in his beautiful canvas, a proposal already in the 19th century, to enjoy nightlife and public lighting without denying ourselves the pleasure of contemplating the sky.

In Spain, the light pollution map published by MITECO leaves little room for doubt: it is increasingly difficult to contemplate and enjoy the night sky in our country, another form of landscape and environmental value that must be cared for and respected as one of the greatest cultural legacies of the human species. Not for nothing, hundreds of astronomy groups and associations have been asking UNESCO for decades to make the starry sky an Intangible Heritage of Humanity.

The skies that we see today from Earth still have the same stars that Omitz contemplated on that night 20,000 years ago, the same stars that heard the first stories of the human species, the same stars that the Phoenicians tracked to reach southern Iberia, the same constellations that inspired the mythology of Greek Olympus. This connects us to immortality, these are the same stars that Newton and Galileo, Cervantes or Julius Caesar contemplated, and, without a doubt, the same sky that Antoine de Saint-Exupéry's Little Prince looked at ecstatic wondering if the stars were illuminated every night for the sole purpose of each of us finding his own.

We invite all of you, on the next dark night, to go out somewhere secluded and contemplate the immensity of the cosmos. It is a journey back in time and a good opportunity to assume the smallness of our existence and the ephemerality of our life. And maybe, then, only then, like the Little Prince, will you also find your own star.

To learn more:

• Universe. Ress Martin (2006)
• Astrophotography. The night landscape. Javier Martinez Moran (2020)
• Celestial Bestiary. What is hidden under the night sky? Aina Berstard (2021)
• Under the night sky. A story of humanity through our relationship with the stars. Stuart Clark (2022)