This is the reverse side of a ~2040 year old, one denarius silver coin issued by the Roman Empire.  The obverse side depicts Caesar Augustus (real name: Gaius Octavian), the first emperor of the ancient Roman Empire - he ruled from 27 B.C. to 14 A.D.  The coin was produced at the Caesaraugusta Mint in Spain (= modern day city of Zaragoza) in 19 to 18 B.C.  
<p>Seen here is a stylized representation of the most famous and brightest, daytime-visible comet in history, Comet Caesar.  It appeared in the summer of 44 B.C., several months after Julius Caesar was murdered by Marcus Junius Brutus and others on 15 March 44 B.C.  The appearance of the comet was interpreted by many as the soul of Julius Caesar.  The text on the coin reads "DIVVS IVLIV" - "Divine Julius".  The comet's tail is depicted at near-12 o'clock.
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<hr><p>Identification: Augustus 37B of "Roman Imperial Coinage, Volume I", Second Edition
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<hr><p>For info. on comets, see the caption at:
www.flickr.com/photos/jsjgeology/50121426266
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<hr><p>See info. at:
en.wikipedia.org/wiki/Caesar%27s_Comet
and
en.wikipedia.org/wiki/Assassination_of_Julius_Caesar
and
en.wikipedia.org/wiki/Denarius
and
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en.wikipedia.org/wiki/Augustus
James St. John
CC BY 2.0
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