NGC Ancients: Astronomy, Part 2

Ancient people were fascinated by what happened in the sky. In our previous column, we looked at coins that portrayed deities of the sun and moon as well as ones that captured snapshots of comets and other phenomena.

This time, we continue our look at coins with heavenly themes, with a particular focus on astrology, the concept that the position of planets and stars affect people's lives. Just as in ancient times, this field of study is of interest in the present day. A YouGov survey in 2022 found that about a quarter of American adults believe in astrology.

By Roman times, the 12 signs of the zodiac were well-established, having been influenced by earlier Greek and Babylonian ideas. This base-metal medallion of Perinthus in Thrace, issued under Roman Emperor Gordian III (A.D. 238-244), shows the signs of the zodiac, beginning with Aries at the top-right and continuing clockwise with: Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces. These correspond to constellations through which the sun's path passes at some point during the year.

This base-metal rarity from Sidon in Phoenicia, bearing the portrait of the Roman Emperor Elagabalus (A.D. 218-222), also shows the zodiac wheel with Aries at top-right, but the signs here run counterclockwise. At the center is a carriage of Astarte, a Syro-Phoenician goddess who was worshipped in the form of a sacred stone (a baetyl). Elagabalus was assassinated at age 18 after he alienated many Romans by promoting the cult of Elagabal, including the baetyl, which likely was a meteorite. (You can see a coin showing it near the end of Part 1 of this column.)

The Roman Emperor Antoninus Pius (A.D. 138-161) issued a series of zodiac-related base-metal drachms in Alexandria, Egypt, including this one that shows Venus in Taurus. These coins were apparently tied to a surge in enthusiasm for astronomical matters amid the completion of a Great Sothic cycle on the Egyptian calendar of 1,460 years (discussed in Part 1 of this column).

This drachm of the same zodiac series shows Mercury above the twins of Gemini. In this case, the twins are portrayed as Heracles (left, with a club) and Apollo (right, with a lyre).

Typically, the Gemini are represented by the Dioscuri (Castor and Pollux), as shown on this Alexandria drachm of Antoninus Pius, with a crescent moon above them. In Greek mythology, Castor and Pollux were phenomenal horsemen who were siblings of Helen of Troy. The two brightest stars in the constellation Gemini are named Castor and Pollux.

This Antoninus Pius drachm of Alexandria shows the moon in Cancer, the crab. The zodiac signs correspond to when the sun is in or near that particular constellation. (They've become somewhat misaligned due to the precession of the equinoxes, which is caused by a long-term wobble in Earth's rotation). Cancer gives its name to the Tropic of Cancer, named for the geographical line about 1,600 miles north of the equator (passing through north Africa, India, Mexico and other places) at which the sun's rays are directly overhead on the summer solstice.

Struck at Mopsouestia-Mopsos in Cilicia, this base-metal coin issued around the time of Emperor Marcus Aurelius (A.D. 161-180) shows a crab with a star. In Greek mythology, Hercules slays a crab that bites him while he was fighting the Lernaean Hydra; the goddess Hera, archenemy of Hercules, then placed the crab among the stars. (Learn more about the Twelve Labors of Hercules on coins in NGC Ancients columns here and here.)

This Antoninus Pius zodiac series base-metal diobol shows the sun in Leo. This particular coin has a diameter of 23 mm (roughly the size of a US quarter) and weighs about 8 grams, much smaller and lighter than the drachms illustrated elsewhere in this column.

This silver tetradrachm struck at Acanthus in Macedon, c.500-480 B.C., shows a popular theme on some of the oldest coins: a lion attacking a bull. The motif can be traced centuries earlier to the dawn of civilization in Mesopotamia. Some have theorized this motif has origins in the constellations of Taurus and Leo, perhaps related to spring giving way to summer.

This Antoninus Pius zodiac drachm from Alexandria shows Mercury in Virgo. The largest constellation in the zodiac, Virgo is often associated with the Greek goddess of agriculture, Demeter, or her Roman equivalent. Virgo is sometimes associated with Astrea, the Greek goddess of justice, which is fitting because nearby stars in Libra appear to form the scales of justice.

The scales of justice are shown boldly on this Antoninus Pius zodiac drachm of Alexandria which shows Venus in Libra. The personification of justice as blindfolded and holding the scales can ultimately be traced to Themis, a Greek goddess who personified the law and was associated with the scales. In ancient times, the autumn equinox (in which day and night are in balance) occurred as the sun entered Libra in late September.

Another Antoninus Pius zodiac drachm of Alexandria shows Mars in Scorpio. One Greek legend relates that the death of the great hunter Orion was due to a scorpion sting. Zeus later placed Orion and the scorpion in the stars, but at opposite ends of the heavens.

Jupiter in Sagittarius appears on this Antoninus Pius zodiac drachm of Alexandria. The Greeks associated Sagittarius with Chiron, a centaur who taught Achilles archery skills and mentored other mythological heroes.

Chiron also appears on this base-metal assarion struck under Emperor Augustus (27 B.C. to A.D. 14) for the Magnetes in Thessaly. Homer's Iliad describes Chiron as "the most righteous of all the centaurs," creatures that were half man and half horse. (See more centaurs and other mythological creatures on ancients coins in NGC Ancients columns here and here.)

Saturn in Capricorn is shown in this Alexandria drachm from Antoninus Pius’ zodiac series. As winter gets underway, the sun approaches Capricorn, which takes its name from the Capricornus constellation with its goat-like shape.

This silver denarius issued under Augustus shows the Capricorn as a sea-goat. At its shoulder is a cornucopia (a symbol of prosperity) and in front, a globe. Augustus was born in September, so it's possible the sign related to the date of his conception. The ancient Roman book "The Twelve Caesars" relates a story of how a prominent astrologer threw himself at the feet of Augustus in awe after learning that Capricorn was his zodiac symbol. Augustus used the Capricorn on many of his coins, aiding the popularity of astrology in ancient Rome.

The symbol of Capricorn was so thoroughly associated with Augustus that it was employed decades later on this silver denarius struck under Emperor Titus (A.D. 80-81). The coin honors the recently deceased — and deified — emperor Vespasian, Titus' father, who is portrayed on the obverse.

This Antoninus Pius zodiac drachm of Alexandria shows Saturn in Aquarius, the water bearer. The Babylonians associated this constellation with the god Ea, who is often shown with an overflowing vase. The ancient Greeks also viewed Aquarius as a vase from which water flowed.

Aquarius is sometimes associated with Ganymede, who’s shown with an eagle (representing Zeus) on this base-metal coin struck for the emperor Marcus Aurelius in at the famous city of Troy (Ilium) in Troas. Centuries earlier, Homer's Iliad described Zeus as being so impressed with the beauty of the young man that he spirited Ganymede into the heavens to serve as his cupbearer. The planet Jupiter (named after the Roman equivalent of Zeus) has the largest moon in the solar system, Ganymede — bigger even than the planet Mercury!

Jupiter in Pisces, which is typically depicted as a pair of fish, usually swimming in opposite directions, appears on this Antoninus Pius zodiac drachm of Alexandria.

Our final Antoninus Pius zodiac drachm of Alexandria completes the 12-month cycle with an image of Mars in Aries, the ram. Though the planet Mars is considered to rule the astrological sign of Aries, there is no others link between Aries the constellation and Ares the Greek god of war (called Mars by the Romans).

There are other constellations in the sky besides the dozen above that the sun transits. This base-metal dichalkon struck ca. 370-340 B.C. at Orchomenos in Arcadia depicts Artemis, the goddess of the hunt, on the observe. The reverse shows Callisto, a nymph of Artemis, who was transformed into a bear after Zeus impregnated her.

Callisto gave birth to Arkas, who gave his name to the Arkadians. Zeus eventually brings mother and son into the heavens as Ursa Major (the Great Bear) and Ursa Minor (the Little Bear). Ursa Major contains the seven stars that make up what is nicknamed "The Big Dipper," while Ursa Minor overlaps with "The Little Dipper," including Polaris (the North Star) at the tip of its handle.

This silver denarius struck under Emperor Hadrian (A.D. 117-138) shows the moon and seven stars, likely a representation of the stars of either the Big Dipper or Little Dipper.

Finally, we share this base-metal coin struck at Coropissus in Cilicia for the emperor Maximinus I (A.D. 235-238), which shows the hero Perseus rescuing Andromeda, an Aethiopian princess who was chained to a rock as a human sacrifice to appease an angered god Poseidon.

Perseus used the head of Medusa, whom he had slain, to defeat the sea monster Cetos, which Poseidon had sent to ravage the Aethiopian coast. She gives her name to the constellation Andromeda as well as an entire galaxy visible within it. Originally thought to be a nebula, Andromeda is the closest spiral galaxy to the Milky Way, and roughly the same size.

Images courtesy of Classical Numismatic Group.