World's Oldest Known Map Of Night Sky Found Hidden In Medieval Parchment [Photo]

A team of researchers has stumbled upon the long-lost star catalog of astronomer Hipparchus in the medieval codex preserved at St. Catherine's Monastery in Egypt's Sinai Peninsula.

The new findings, published in the Journal for the History of Astronomy, give weight to the idea that it was indeed Hipparchus who made the first attempt to map the sky.

James Evans, a historian of astronomy at the University of Puget Sound in Tacoma, Washington, called the finding "rare" and "remarkable."

It all started in 2012 when Jamie Klair, a student of biblical scholar Peter Williams noticed something odd about the lettering of the Christian manuscript he was working on at the University of Cambridge. Klair found a passage in Greek credited to astronomer Eratosthenes.

The document consisted of the Codex Climaci Rescriptus, which is a collection of Syriac texts written in the 10th or 11th centuries.

Multispectral imaging of the document in 2017 revealed that the manuscript seemed written over. This in itself was not suspicious since it was common to reuse old parchments, which were considered very valuable commodities in those times.

The nine folios of pages that were found in the document had certain interesting numbers. The folios were probably written in the 5th or 6th centuries and included star-origin myths from Eratosthenes and excerpts of a renowned 3rd Century-BC poem called Phaenomena.

When Williams passed on the document to scientific historians in France, the researchers were taken aback.

"It was immediately clear we had star coordinates," Historian Victor Gysembergh, of the French National Scientific Research Center in Paris, told Nature.

The style of writing in the folios was similar to that of Hipparchus. Moreover, backtracking the current star positions to the ones mentioned in the parchment put the coordinates around roughly 129 BC. This coincides with the period when Hipparchus was working.

Until now, astronomer Claudius Ptolemy was considered the first to attempt a star catalog in the 2nd century AD – His work on star coordinates is the only one to have survived.

However, many ancient manuscripts cited Hipparchus as the first person to have measured the stars. The astronomer worked on the Greek island of Rhodes three centuries before Ptolemy, roughly between 190 and 120 BC.

It was difficult to decipher the newly found document, with the coordinates of only one constellation, Corona Borealis, was clear.

The parchment from Egypt "represents countless hours of work," noted Gysembergh. It was so because the work was from before the era of telescopes. Gysembergh believes Hipparchus most likely mapped the sky using a sighting tube, known as a dioptra, or a mechanism called an armillary sphere.