by Danielle Alexander
December 30, 2020
the scenic lake of Llyn y Fan Fach
Brecon Beacons Dark Sky Reserve
Huw James Media
In modern astronomy, this constellation is often divided into two or
One is a female water
snake called Hydra, the other, Hydrus.
constellation located in the southern hemisphere, Hydrus is
considered the male counterpart of this giant, sprawling star
At twenty-seven stars,
this is the largest constellation in the sky, visible from almost
anywhere around the world.
Unfortunately, it lacks
particularly bright stars, so can be difficult to spot. The
brightest, an orange star named Alphard, meaning solitary
in Arabic, is so named due to its seeming loneliness in the abyss.
The six stars that form the snake's head are the constellation's
most distinctive feature. The head has a culmination on January 31st,
whereas the tail culmination occurs during April.
Culmination is when the
constellation, or in this instance part of the constellation,
reaches the zenith of the celestial sphere's rotation, appearing
higher in the sky.
An artistic impression of Hydra
its surrounding asterisms.
In case you haven't noticed, humans have a curious fascination with
the night sky.
Some of the stories we
"see" as constellations go all the way back to Mesopotamian times
(1300-1000 BC), where sky-watching was a prestigious occupation.
Gradually, early astronomy developed a mythic component.
Over time, different
narratives evolved in response to changes in interests and values
over the generations, reflected in patterns in the sky. These
narratives likely experienced dramatic development during the
transition from oral to written transmission, but to what is extent
Today, the International Astronomical Union lists 88 official
constellations, many of which date back to Ptolemy's seminal
work on astronomy,
The Almagest (A.D 150).
Compared to the rest of the ancient world, the Greeks began
investigating the stars rather late (Hesiod and Homer,
500 BC). As such, they incorporated a lot of astronomy from their
The Greek astral mythos
canon was solidified by Eratosthenes, in a work now lost to
Across the Sky
Hydra was identified as far back as
ancient Sumer, where it was named
after the primordial salt-water dragon goddess, Tiamat.
In the myth, Tiamat
slaughters the inhabitants of Earth, her offspring with Abzu/Apsu,
the primordial god of fresh water, after they had slain her
As myth and time
progressed, she was usurped by the storm god
Marduk, who overthrew the queen
to gain divine regency amongst the Mesopotamian pantheons.
The introduction of Marduck, Babylon's supreme deity, reflected the
increase of political power that Babylon had over the Sumerian and
Akkadian states of Mesopotamia.
In this way, the
Mesopotamian myth of the serpent contains a simplified,
mythologized history of the region.
The serpent also held importance in Egypt, where it was likened to
the unfurling, curling nature of the Nile, signifying changes in
zodiacal alignments and celestial events.
However, in ancient Greece, this constellation was the formidable
Lernean Hydra, the second of
the great Labors of Heracles.
The story goes that
Hercules was set against the Hydra, mythological monster with nine
heads that oozed venomous substances from gaping jaws.
The offspring of Typhon and Echidne, reared by Hera, the Hydra was
terrorizing the sacred and fertile region of Lerna, near Argos. On
ancient Greek coins, the Hydra is stylized with seven heads to mimic
the river Amymone, where it was said to have lived prior to invading
the Lernean swamp.
The problem of the
multiple heads couldn't be resolved by decapitation due to their
fierce regrowth, sprouting two or three more heads from their bloody
Heracles, with the aid of Athena, tempted the Hydra out of hiding
with flaming arrows and held his breath when it emerged.
He then lopped off its
heads, but they just grew back. The twisting tail sought to trip him
as it gripped his ankles and he uselessly waved his club around.
Hera, determined to see
the young hero fail, sent a crab to pinch his feet. It was swiftly
This then became the
astrological constellation of Cancer.
Hercules and the Hydra
The flailing and ever-increasing number of heads was becoming
overwhelming for Heracles, who was saved by his charioteer, Iolaus.
Iolaus heroically set fire to the
grove in which the battle occurred and waved burning branches at the
fresh stumps, cauterizing the wounds and preventing their regrowth.
This also provided
sufficient distraction for Heracles, who was able to access the
golden head of the Hydra and remove it with a golden falchion (a
type of sword), thus claiming victory over his second trial.
He then dipped his arrows
into the disemboweled body of the monster. However, his victory was
short-lived as Eurystheus, who had set the trial, held that
Hercules had cheated because he received assistance.
Lerna was known as the location where Dionysus had ventured to
the Underworld, and so housed several divine shrines to the god,
where secret nocturnal rites were performed.
Mysteries of Demeter were celebrated there, in a shrine set at
the locale where Hades took Persephone to the Underworld.
It appears this location
was a hotspot for traversing realms.
Robert Graves (The
Greek Myths) has suggested that this classical mythology
was a historical attempt to suppress the archaic fertility rituals
of the Mysteries that took place there.
Urania's Mirror, 1825
Hydra actually has two constellations perched on its back:
This peculiar combination
is associated with Apollo's punishment of the Crow.
The tale goes that the
bird was sent by Apollo to retrieve water for a ritual libation.
Unfortunately, some figs distracted his feathered friend while on
The Crow waited several
days for the figs to ripen in order to pluck the delicious snack
from the tree and gobble them up, having forgotten his heaven-sent
Once his tummy was full, the Crow suddenly remembered - the water
for the gods!
In a bid to save his own
feathers, he snatched a water-snake and brought it before Apollo,
claiming it had consumed all the spring water. Apollo, seeing the
ruse, cursed the Crow to suffer from thirst during the season of fig
In order that the crime
would not be forgotten, Apollo put the imagery into the heavens,
with neither the Snake nor the Crow able to reach the bowl of water.
In some versions, the Crow returns with a bowl of water, albeit
several days late, and the Snake was only placed amongst the stars
to deter the Crow from the bowl.
This is not the only
story involving Apollo cursing the Crow, and it makes you wonder why
he kept them in employment!
Constellation in Troy
Image showing Hydra in the southern sky
around 9 pm ET, mid-latitudes, Northern Hemisphere.
© Starry Night Software
The Bowl, also known as the Crater, is a constellation
in its own right and has mythological roots going back to Troy.
While the city was
ruled by Demophon, it was plagued with a... well, plague.
distraught by the epidemic, invoked Apollo, who had worked with
Poseidon to construct Troy and so favored the city.
In order to stop the
plague, Apollo demanded a maiden of noble origin be sacrificed
to the patron god of the cities every year.
Demophon devised a system in which all the noble women would be
sacrificed except his own daughters.
This worked for a
while, until another noble family patriarch, Mastousios,
refused to enter his daughter.
The king, outraged,
ordered that his daughter be sacrificed, without drawing lots.
Mastousios played the long game and did not seek immediate
retribution against the king. He pretended to befriend him, and
spent a year winning his favor.
When it came to the
sacrifice, he informed the king he had chosen a victim this year
and organized the ceremony. The king, no doubt busy with royal
affairs of state, sent his daughters ahead of him with a wave
and a "I'll meet you there."
The vengeful noble Mastousious slaughtered the king's daughters
and mixed their blood into the wine that he presented to the
King upon his arrival.
plan came to a bad end when the King realized what had happened
and threw Mastousious into the sea.
This body of water
retained the name, and the event was placed into the sky as a
reminder against abusing power for one's own benefit.
This tale does not bare much resemblance to the imagery presented in
the stars. It appears to have been created to provide an origin for
the harbor and sea name in the region, rather than being
representative of the story around the constellation.
The serpent in the stars reflects the tales of love,
betrayal, and political upheaval.
The size of this
constellation reflects the variations of mythos surrounding it,
regardless of whether it is seen entirely as Hydra or divided into
the crow and the crater.
As the story of the bowl
constellation in Troy demonstrates, some Greek tales almost seem
forced into place.
The serpentine motif is
predominantly associated with the pre-Olympian pantheons and the
primordial Tiamat, yet it continues
to dominate today by taking up the largest part of the night sky.
(2005) - The complete guide to the constellations - London:
Hygin, Aratus and Hard, R. (2015) - Constellation myths -
Oxford: Oxford University Press, pp.110-114
(1940) - Apollo and the Sun-God in Ovid - The American
Journal of Philology, 61(4), 429-444. doi:10.2307/291381
Graves, R. (2012)
The Greek Myths - New York:
Kirk, G. S.
(1972) - Greek Mythology: Some New Perspectives - The
Journal of Hellenic Studies, 92, pp.74-85
Bousoulegka, E., Nyquist, A., Castro, B., Alotaibi, F., &
Drivaliari, A. (2017) - New evidence from archaeoastronomy
on Apollo oracles and Apollo-Asclepius related cult -
Journal Of Cultural Heritage, 26, 129-143. doi:
(2006) - The Origin of the Greek Constellations - Scientific
American, 295(5), pp.96-101.