The most sophisticated mechanical device of ancient Greece may finally be giving up its secrets.

Researchers have long known the so-called Antikythera mechanism was a calendar of sorts that represented the positions of the sun and moon using a series of gears. In its complexity it outshined all other objects for a thousand years following its creation sometime around the first century B.C.

Now an international consortium of researchers has probed the machine’s corroded fragments with sophisticated x-ray and light imaging tools to uncover the true sophistication of this geared wonder.