There are many odd figures among the stars. To our eyes, the strangest is Capricon, the goat-fish.
Not only is the concept of a half-goat/half-fish somewhat outlandish, the constellation is among the most difficult to visualize. Ptolemy assigns stars to the head and foreleg of a goat, and to the fin and tail of a fish; but it’s not easy to draw a goat-fish which encompasses these stars as described.
After staring at Capricorn’s stars for a while, and pondering the history of the Mesopotamian stars, we’ve got a proposal for how this might have come to be.
The constellations of the Zodiac were defined by Assyrian and Babylonian astrologers, who tracked the motions of the planets against the background of the fixed stars. Or more accurately, a band of the fixed stars, for the wandering stars kept to a particular part of the sky.
It appears that in the evolution of Mesopotamian astrology, the stars of the Zodiac were mapped in order of obviousness. (See Rogers in the Reading Room). Iconography from 4500 years ago features bulls and lions and scorpions, figures which are among the most prominent of the Zodiac; this is evidence that the roots of the Zodiac are at least that old. But while much of the Zodiac presents bright stars and striking asterisms, the stretch of sky through Capricorn, Aquarius and Pisces features some of the most unremarkable stars of the Zodiac. Nevertheless, the stars where the planets wandered had to be mapped, for better or worse; in the course of this effort, the goat-fish was spawned.
The stars of Capricorn are not very bright; best viewed on a moonless night. Four of 3rd magnitude, nine of 4th, nine of 5th, and six more even dimmer. The astrologers of Mesopotamia, we suspect, found little to note in these stars.
Following Capricorn in the sky are two arbitrary figures. Aquarius, the Water-Bearer, is depicted with an urn on his shoulder, from which a stream of water flows. And Pisces represents two fishes, both tied to lines. Looking at these stars, it’s difficult to imagine somebody staring at them and deciding ‘that star and that one and that one there, along with those two – that looks just like water splashing down a hillock’. If you try to simply point and say ‘that star, and that one, and that—no, not that one, that one—doesn’t that look like water flowing from an urn and spreading on the ground?’, your friends will politely nod and suddenly remember that there’s something else they’re supposed to be doing right now. Same with the stars of the fishlines of Pisces; there’s nothing about these stars that jumps out and says ‘this is a fisher’s line, bearing a fish’. One might purposefully map them as such; but nobody intuitively saw them so.
And then there’s the Goat-Fish. Instead of fitting nondescript stars to a nondescript image, the stars of this patch of sky are forced to fit a fabulous creature, which figures in approximately zero tales of ancient myth.
Curious, that.
These three constellations, we suspect, were invented by Mesopotamian astrologers to map this part of the sky.
While the stars of Pisces and Aquarius are nondescript, they’re flanked to the north by the great square of the Horse and the grand triangle of Deneb/Vega/Altair, with the very bright star Fomalhaut to the south, as well as Mira of Cetus. Together, these provide landmarks north and south for drawing starlines criss-crossing the Zodiac belt between. These starlines helped to define secondary and tertiary stars, which were cobbled together into figures. These aren’t obvious stars; one has to learn how to see them.
Capricorn is enigmatic. The head and forelegs of a goat, fused to a commensurate fishtail (with a twist in it). We can’t remember the proper scholarly way of expressing ‘WTF?’, so let’s just say, whoa! That’s some very weird sh– uh, stuff.
Our guess is that the astrologers of Mesopotamia adopted a Mediterranean constellation – but something went wrong in translation.
Sailors and fishers of the Mediterranean region must have been familiar with what we call dolphins or porpoises.
It’s not a big stretch to argue that they might have called them Sea-Goats or Goat-Fish.
Both goats and dolphins travel in packs, and both are known as acrobats. And both are startlingly clever. We can easily imagine a fisher or sailor of the fourth or third millenium BCE making the association, and calling this creature a goat-fish or sea-goat.
(We’ll be reaching out to experts to ask if there’s linguistic evidence to support this conjecture.)
And as it happens, the stars of this region are easily mapped onto the figure of a dolphin.
The stars of Capricorn, as described by Ptolemy, are most especially unobvious.
But these very stars are easily mapped onto the figure of a dolphin.
Flip through chapter 23 of the Starlines (Ptolemy/Capricorn) to see this argument illustrated.
Once seen, it’s hard to un-see.
So.
We presume that when it came time to assign figures to unoccupied patches of the zodiac, the astrologers of the period had a difficult time envisioning a figure to fit the mostly-dim stars of Capricorn. And as Capricorn lies close to the horizon at Mesopotamian latitudes, there were few landmarks available to map these stars with starlines. (These stars were unnamed for a reason.)
We further presume that the experts involved in this process would have included some with knowledge of foreign constellations – those of Egypt, those of the Levant. We can easily envision someone at the table mentioning that the sailors of Phoenicia call these stars the Goat-Fish; the rest of the committee, weary of mapping out ropes and waterfalls, quickly seconds and passes a motion which was never formally declared, in time to break for the day.
Someone who had never seen a dolphin was tasked with naming the stars of the goat-fish, leaving us with the twisted tail of Capricorn.
Some will accuse us of simply making up stories.
We’ll agree to the ‘making up stories’ part – but it’s far from simple.
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Many of the chapters of The Starlines of Almagest address the matter of defining the stars of various constellations by use of star alignments.
For Pisces, see LINK and LINK.
For Aquarius, LINK and LINK.
For Fomalhaut and the southern Fish, LINK.