Researchers in Italy finds detailed map of the night sky dating back to more than 2,400 years ago

In a recent discovery in Italy, researchers have unearthed detailed maps of the night sky dating back more than 2,400 years. The findings, published in the journal Astronomical Notes on November 22, describe a circular white stone with a carved map discovered at an ancient fort in northeastern Italy. The map, roughly the size of a car tire, features 29 engravings, and through statistical analysis, researchers concluded that humans created these engravings. Italy’s National Institute of Astrophysics reported that all but one of the sculptures match the stars in the night sky, including constellations like Orion, Scorpius, and the Pleiades.

The researchers found that the map is “very complete, with all bright stars represented.” It’s suggested that people might have used the map to track seasonal changes, particularly before engaging in agricultural activities. The study dates the map from 1800 BC to 400 BC, making it one of the earliest depictions of the night sky.

While the map is generally accurate, one engraving doesn’t match any existing star and poses challenges for interpretation. The researchers suggest that the anomaly might be explained by the presence of a bright star that produced a supernova or a failed supernova that left behind a black hole.

Despite the sophistication of the ancient map, the study notes that creating such maps doesn’t necessarily require advanced knowledge of space. Basic measuring tools like the width of a finger or a simple ruler, along with basic counting skills, could be sufficient.

Around 2,200 years ago, the Greek astronomer Hipparchus developed a method to understand the motion of stars, creating the first known star catalogue. He used a coordinate system similar to latitude and longitude to measure the precise position of stars, imagining Earth at the center of a celestial sphere. Although historians are uncertain about how Hipparchus precisely measured stars, they assume he might have used an armillary sphere, a mechanical device depicting the various parts of the celestial sphere with rotating rings. The oldest evidence of stellar coordinates from Hipparchus was found in an 8th-century AD Latin translation of a poem about constellations.