Stories of the Cosmos: The Sky That Sowed the Earth

More than 10,000 years ago, when human communities abandoned nomadism and began domesticating plants, it became necessary to establish a temporal order. When to sow? When to expect rain? These were common questions whose answers were written in the firmament.

Archaeological sites such as Göbekli Tepe in present-day Turkey show astronomical alignments that suggest that early farmers linked sky observation with the organization and development of their crops .

When we think about agriculture, we usually imagine the earth, water, and seeds, without dwelling on the sky as a silent protagonist in this story, but it is clear that, since the first crops, humanity learned that looking up was as important as looking down .

Celestial cycles, such as that of the Sun, marked the rhythm of sowing and harvesting, making astronomy a fundamental ally of agriculture. It's no secret that lighting is crucial in food production, with sunlight being the primary source of energy for plants.

In Mesopotamia , in the area known as the Fertile Crescent, bathed by the Tigris and Euphrates rivers, and where the Neolithic revolution is considered to have originated, which represented a radical change in humanity's way of life, from nomadic to sedentary, the observation of the firmament served to predict floods and harvests .

In Egypt, the appearance of the star Sirius on the horizon just before dawn heralded the flooding of the Nile , without which such a successful civilization would not have been possible. Meanwhile, in Babylon, clay tablets with notes about celestial bodies are preserved, which were used to determine the ideal time for pruning or harvesting. In all these cases, astronomy was the tool that ensured survival.

Our American continent was no stranger to these ideas, and its native peoples also wove their agricultural calendar with threads of stars. The Maya built observatories like the one at Chichén Itzá to record the movements of the Sun and predict essential cycles for growing corn . In the Andean highlands, some 16th-century chroniclers described how farmers observed not only the stars but also the intensity of the zodiacal light, that faint glow in the sky caused by interplanetary dust. Its more or less marked brightness in certain seasons served as a signal to adjust agricultural practices.

Nowadays, with satellites measuring soil moisture, tracking storms, and climate prediction systems, it might seem like we no longer need space science. However, the same astronomy that helped ancient people organize their agricultural lives now offers us images from space to monitor crops, measure deforestation, or predict droughts.

On World Agriculture Day , celebrated every September 9, it is good to remember that one of the oldest activities for the subsistence of humanity was born under a sky full of questions, and that the wheat, corn, and rice that sustain humanity today were made possible thanks to knowledge that united earth and stars.

Astronomical Observatory of the National University