New Numismatic Evidence about the Comets of Mithradates the Great of Pontus (134 and 119 BC).

The historian, Justinus, tells us that the life of Mithradates the Great of Pontus (ca. 134 - 63 BC) was marked by two unusually large comets: one at his birth in ca. 134 BC and another at his coronation ca. 119 BC. Often these comets are cited as proof that sometimes comets heralded great, good events (such as the Star of Bethlehem.) We now have evidence that counters that notion. Mithradates struck some bronze coins that depict a foreboding hippeus (horse) comet. Pliny, the Roman naturalist, tells us that this kind of comet had plumes much like horses manes in very rapid motion and moving in a circle. The evidence is that the horses mains are synchronic bands. The visibility of these bands indicates that the hippeus comet is a class of comets that had a close encounter with the earth, perhaps on the order of a million kilometers. Hephaistion of Thebes tells us that the hippeus comet foretold the quick fall of kings and tyrants and rapid changes in the affairs of these countries. It is likely that the comet was interpreted as an omen of violent revolution, but Mithradates apparently altered the focus of the portent, namely that the comet signified his struggle to evict the Romans from Asia Minor.