World’s First Star Map Has Been Discovered in a Medieval Manuscript

The world’s oldest complete star map might have just been discovered. The segment is believed to be a copy of the long-lost star catalog of Greek astronomer Hipparchus. The unique discovery was found beneath the text on a sheet of medieval parchment. The fragment was concealed beneath a religious book in a monastery in Egypt’s Sinai Peninsula.

Where the Discovery Was Made

A fragment of the Christian codex which holds the world's oldest complete star map.

Codex Climaci Rescriptus, the book where the find was uncovered, is a palimpsest. That means its original wordings have been removed from the parchment to make way for the Christian Palestinian-Aramaic texts. Scholars found that even older texts lie beneath the pages of the Codex.

What was more surprising, though, was that the multispectral images found numbers stating the length and width of the constellation Corona Borealis in degrees. The coordinates of the stars at the farthest corners of the constellation were also listed. In other words, they found the first complete star map. The finding was published in the Journal for the History of Astronomy.

Who Created the First Star Map?

A depiction of an ancient astronomer.

Thanks to the precise coordinates written in the segment, scholars have been able to determine the rough date when they were written down – roughly 129 B.C. That’s about the time when Greek astronomer Hipparchus, also known as the “Father of Scientific Astronomy”, lived. He’s known to have spent his later years primarily making astronomical observations. We don’t have much information on his life, for much of it has disappeared over the centuries. Still, we know that many historical documents give him credit for a number of important scientific advances. One of them is accurately modeling the motions of the sun and the moon. He’s also been able to establish a scale on which stars are measured using their brightness.

According to historical documents, Hipparchus, who’s believed to have created the first star map known to man, saw something in 134 B.C. when observing the night sky: a new star in what was before a patch of empty space. Pliny the Elder, a highly famed naturalist in the early Roman empire, commented in his book Natural History that Hipparchus’s discovery “led him to ponder whether this was a frequent occurrence and whether the stars we believe to be in a fixed position are also moving.”

How the Map Was Created

Saint Catherine's Monastery in Sinai, the place where the star map was discovered.

Hipparchus went on to catalog a whopping 850 stars across the night sky, observing their brightness and precise location. By comparing his complete star map with individual measurements of some stars made by other astronomers, he conducted that the distant stars appeared to have moved two degrees from their initial position.

He even correctly concluded the reason why this happens. Earth was processing, thus wobbling on its axis at the rate of one degree per 72 years. The star chart created by Hipparchus, along with all of its copies, had been lost up until now.

Apart from the Codex Climaci Rescriptus, scholars believe there could be more pages of the star catalog hidden beneath the 160 palimpsests at St. Catherine’s Monastery. Previous examinations have led to the discovery of previously unknown Greek medical texts which depict surgical instructions, guides to medicinal plants, etc.