For centuries, humanity believed this treasure to be lost forever in the fires of history. A map of the starry sky created by Hipparchus, the great astronomer of antiquity, was hidden beneath layers of medieval religious texts. Today, thanks to powerful X-rays and particle physics, we can finally see the constellations through the eyes of a person who lived two millennia before the invention of the telescope.
The story of this discovery resembles a real detective story that has stretched over thousands of years. At the center of events is a 6th-century manuscript called Codex Climaci Rescriptus. In the Middle Ages, parchment was extremely expensive and scarce, so monks often resorted to “recycling”: they washed or scraped off the old text and wrote new text on top of it. Such manuscripts are called palimpsests.
This particular manuscript, originating from St. Catherine’s Monastery on the Sinai Peninsula (the oldest Christian monastery in the world), concealed something much older beneath its Syrian script. Back in 2022, researchers suspected that Greek symbols describing the coordinates of stars were hidden beneath the surface. Preliminary analysis showed that these records perfectly match the state of the night sky during Hipparchus’ time, taking into account precession — the slow oscillation of the Earth’s axis, which changes the appearance of the starry sky over millennia.
Hipparchus: father of accurate astronomy
Who was Hipparchus, and why is his map so important? Hipparchus of Nicaea (190–120 BC) is considered the first true astronomer of Western civilization. He was the first to map the trajectories of the Sun and Moon and create the world’s first systematic catalog of stars.
Until now, we knew about his work only from the comments of other authors or from his own critical notes on the works of others. His main work, a complete star map, was considered a myth until modern science made it possible to “break through” the layers of medieval ink. Hipparchus did not simply draw stars; he measured their coordinates with a precision seemingly impossible for observations made with the naked eye. His work became the foundation upon which all modern astronomy is based.
Synchrotron instead of a magnifying glass: physics in the service of history
To unravel the mystery of the Codex Climaci Rescriptus, the manuscript was taken to the SLAC National Accelerator Laboratory in the United States. Here, scientists used a synchrotron — a giant particle accelerator. In it, electrons are accelerated to nearly the speed of light, generating high-energy X-rays.
This method allows chemical substances in a sample to be identified without damaging it. The secret lies in the ink: medieval monks used iron gall ink, while Hipparchus’ original text was written with a different composition that left behind a calcium trace. X-ray scanning allows us to “filter out” the iron and see only the calcium “skeleton” of ancient Greek letters.
“I am at the height of excitement,” says historian Victor Gysembergh of the CNRS. “Line by line, texts that no one has seen for over a thousand years are appearing on the screen.” The first scanned pages clearly show a description of the constellation Aquarius and precise coordinate figures.
Jewelry work and the global puzzle
Transporting and scanning a manuscript is an operation of the highest level of complexity. Special frames and cases with strict humidity control were created for the manuscript. The lighting in the scanning room is minimal so that the light does not damage the fragile parchment.
At present, only 11 of the approximately 200 pages contained in the codex have been scanned at the SLAC laboratory. The problem is that the pages of this manuscript are scattered across various collections and museums around the world. Now scientists need to coordinate their efforts to put this cosmic puzzle together.
Why is this important?
The restoration of Hipparchus’ map is not just an archaeological find. This is the answer to fundamental questions of science: how did we begin to understand the Universe? Why did people suddenly become so skilled at measuring cosmic distances more than two thousand years ago?
Hipparchus’ accuracy proves that ancient science was much more advanced than we tend to think. These coordinates are the first steps of the human mind toward the stars. And the fact that we can read them using a particle accelerator is the best proof of the continuity of our quest for knowledge.
We have only just begun to read this “lost book” of space. There are still hundreds of pages ahead that could radically change our understanding of the origins of European science.
Earlier, we reported on what our distant ancestors saw in the sky without telescopes.
According to sciencealert.com
