Constellation Hydra The Water Snake

Learn how Hercules defeated Hydra the multi headed Water Snake, which grew two new heads every time he cut one off. Find out more about the 88 constellations at Name a Star.

 Symbolism: Hydra the Water Snake, the largest constellation in the night sky.

Mythology: The oldest stories come from Hindu and Chinese mythology referring to dragons. Stories better known in the west come from ancient Greece describing a mythological hybrid of serpent, lion and bird. One myth associates Hydra with a crow that is sent by Apollo to fetch a cup of water. The crow stops to feast on figs instead of collecting water. The crow arrives with a water snake in a cup and no water, then blames the snake. Apollo saw through the fraud and angrily cast the crow, cup, and snake, into the sky. (Corvus, Crater, and Hydra).

In a more exciting myth, the multi headed monster Hydra grows two new heads every time Hercules cuts one off. Hercules enlists his nephew, Iolaus, to sear the necks with a torch to prevent them from growing back. This enabled Hercules to overcome the Hydra and trap it under a rock.

When is it visible?  Best seen from the southern hemisphere, but can be observed in the north between January and May.

How to find it? Hydra spreads across the sky from horizon to horizon in the south.

History:  A similar constellation dates to the Babylonian star catalogs that list two serpent related constellations. Hindu Mythology and Chinese Astronomy mention equivalent constellations associated with dragons. The Hydra constellation recognized today was first catalogued by the Greek astronomer Ptolemy in the 2nd century. Hydra is one of the 15 equatorial constellations. It contains seven stars named by the International Astronomical Union (IAU), which leaves all of the rest of the Hydra constellation stars to be named as gifts at Name a Star.