The Antikythera Mechanism (National Archaeological Museum, Athens, inv. X 15087) was a Hellenistic gearwork device for displaying astronomical and chronological functions. Substantial but highly corroded remains of the instrument were recovered from an ancient shipwreck (see Figure 1).
The most complex scientific instrument to have survived from antiquity, it resembled the sphaerae or planetaria described by Cicero (1) and other Greco-Roman authors. The date of its construction is in dispute but must have been earlier than the middle of the 1st century