10 Euros Ptolemy's Astrolabe

Part of Greece's ongoing "Sciences of the Ancient Greeks" series, this issue commemorates the astrolabe — an instrument whose attribution to Ptolemy or his immediate circle remains contested among historians of ancient technology, though its theoretical foundations are traceable to his Planisphaerium. The Bank of Greece has used the series to anchor modern numismatic output to a recoverable national intellectual identity, particularly relevant given the sovereign debt crisis that nearly ended Greek euro coinage entirely in the early 2010s.

KM#409 assigns this a relatively late catalog position within Greek euro commemoratives, reflecting just how extensively Athens has mined ancient scientific heritage as a mint theme since the mid-2000s.