What remains of the device today is a delicate shell of what it once was, and just a fragmented piece at that. It’s on display, in three pieces, at the National Archaeological Museum in Athens. Each piece is small enough that you could, theoretically, pick it up—though it’s far too frail for such handling. “The mechanism is like the consistency of pastry, like filo dough,” said Brendan Foley, a marine archaeologist from Woods Hole Oceanographic Institution who spent several weeks diving the wreck this spring. “It’s really fragile.”

Yet scientists have been able to do remarkable research on what they have. In the past decade, 3D scanning technology has helped reveal the inner workings of the device—including a set of interlocking gears—and an intricate set of inscriptions on the mechanism. Now, for the first time in the century since the Antikythera Mechanism was pulled from the sea, an international team of researchers has translated a significant portion of the text inscribed on the device. They published their findings in the science and history journal Almagest in May.

“It’s a lot of detail for us because it comes from a period from which we know… essentially nothing about the technology, except what we gather from here,” Alexander Jones, a professor of the history of ancient science at New York University, told the Associated Press. “So these very small texts are a very big thing for us.”

Big enough to determine that the mechanism was, Jones says, something of a “philosopher's instructional device,” and the text itself was a guide to reading it.

Researchers believe the machine was once housed in a vertical rectangular case with calendrical dials and inscriptions on both the front and back. A hand-crank on one side of the machine would have turned the gears that moved the dials—so that anyone using it could determine the precise position of the sun and the moon on a given day. (The dials on the back reflected these cycles in greater precision.) The mechanism could also tell you when lunar and solar eclipses would occur, and tracked the timing of the Olympic games. Such events, as the writer Sarah Kaplan pointed out, were seen as inextricably linked in antiquity. Eclipses were believed to have ominous implications; so it makes sense that you might want to know if an important cultural event overlapped with one.

An astonishing level of complexity would have been required to represent astronomical data this way, yet researchers say the mechanism was more of a textbook used for teaching than a computer used for calculating, as it has often been described.

The newly translated inscriptions also give researchers an idea of the pieces of the mechanism that have long since vanished, including a display of tiny spheres which would have represented the movement of the sun and several planets on the front of the machine. “The best preserved passages include descriptions of features on lost parts of the Mechanism,” the authors of the recent paper wrote. A display of pointers were attached to small spheres that the sun and planets, they said.