As a single-engine prop plane soars over the high desert of southern Peru, the dull performance of sand and wind-torn rock begins to organize and change form. Distinct white lines gradually emerge from the pale landscape, revealing deep tracks crisscrossing the cracked land like obscure roadways. The plane buzzes along against harsh sunlight before veering at sharp angles so its camera-ready passengers can glimpse what lies below: first trapezoids, rectangles, straight lines and swirls; then, as the tracks begin to form more elaborate shapes, a hummingbird, a spider, an astronaut, a monkey.

These are Peru’s famous Nazca Lines—the subject of mystery for almost a century. How were they formed? What purpose could they have served? Were they the work of aliens? Read on to learn more about the mystery dwelling in Peru’s arid coastal plains.

The Story Behind the Lines

Etched out of the barren desert landscape by ancient indigenous people for reasons which are still largely unknown, the lines are found in a region of Peru that receives less than one inch of rainfall every year, just over 200 miles southeast of Lima near the modern town of Nazca. In all, there are over 300 geometric figures, 800 straight lines, and 70 animal designs, called biomorphs. The biomorphs range from 50 to 1200 feet in length, while some of the straight lines run up to 30 miles.

The lines are referred to as geoglyphs—drawings on the ground made by digging a 12-15 inch trench in the rust-colored upper strata, which exposes the lighter earth underneath (a “negative” image). Because there is so little rain and wind-erosion in this region, the exposed designs have remained mostly intact for 500 to 2000 years.

Peruvian archaeologist Toribio Mejia Xesspe was the first to carefully study the glyphs back in 1926. But since the lines are practically impossible to distinguish from ground level, they were only brought to public attention when a pilot found them while flying overhead in 1939. Researchers flooded the area in the ensuing decades, and a range of theories quickly emerged. Most agree that the majority of the lines were created by the Nazca people, who flourished in the region from around 1 CE to 700. But archeologists have recently uncovered 50 previously unknown tracks that are centuries older than those credited to the Nazca, dating between 500 BCE and 200 CE. This is one of the factors that has made the Nazca Lines a source of obsession and wonder for decades—the exact time of their inception, let alone their purpose, is still a mystery to even the most erudite investigators.

The Theories

On June 22, 1941, just one day after the winter solstice, American professor Paul Kosok found himself standing after a long day’s work at the base of one of the lines. He discovered that the sunset was in direct alignment with the line and quipped that the 310 square mile expanse of high desert in southern Peru was “the largest astronomy book in the world.” Most scientists and archaeologists agreed.

Then came German archeologist Maria Reiche, who studied the glyphs for 40 years and became known as the “Lady of the Lines.” Like Kosok, she argued that the lines served an astronomical and calendrical purpose, which held true until the 1970s when a group of American researchers arrived in Peru to follow up on her conclusions. They quickly discredited her astronomical/calendrical account—not to mention the flimsy theories of the 1960s insisting aliens were involved—and brought a new, multidisciplinary approach to analyzing the lines.

“Look at the large ecological system,” said Johan Reinhard, a National Geographic correspondent. “What’s around Nazca, where were the Nazca people located?—It seems likely that most of the lines did not point at anything on the geographical or celestial horizon, but rather led to places where rituals were performed to obtain water and fertility of crops,” wrote Reinhard in his book The Nasca Lines: A New Perspective on their Origin and Meanings.

A second National Geographic writer, Anthony Aveni, reached similar conclusions: “Our discoveries clearly showed that the straight lines and trapezoids are related to water—not used to find water but rather used in connection with rituals.”

The theory maintains that rituals were likely involved in the archaic need to appease the gods and plead for water—and the biomorphs largely support this finding. Reinhard points out that animal symbolism is common throughout Peru and is featured in many of the desert drawings. Monkeys, for example, are found in the Amazon—an area with plentiful water—spiders are believed throughout the Andes to be a sign of rain, and hummingbirds symbolize fertility.

“No single evaluation proves a theory about the lines,” says Reinhard, “but a combination of archeology, ethnohistory, and anthropology builds a solid case.”

As for the astronaut etched into the desert floor—well, that’s still a mystery.

By: Nico Picciuto