The Constellation Aquarius: The Water Bearer in the Sky's Sea

Aquarius pours from a jar into a region ancient skywatchers filled entirely with water: fish on either side, a whale nearby, a river running beneath it. This is the eleventh entry in a twelve-part series on the constellations behind the zodiac signs, following the sea-goat before it.

A neighborhood made entirely of water

Babylonian astronomers named this figure GU.LA, the Great One, a god pouring two streams from an overturned vase, and placed him at the center of a whole watery district of the sky. Pisces flanks one side, Cetus the whale drifts below, Eridanus the river winds off to the west, and Piscis Austrinus sits directly beneath Aquarius's jar to catch the water it pours. Ancient astronomers had a name for the whole cluster: the Sea. No other stretch of the zodiac gathers this many water constellations into one neighborhood.

Who is the water bearer in Greek myth?

Ganymede, a Trojan prince so beautiful that Zeus had him carried off to Olympus to serve as cupbearer to the gods, replacing Hebe in the role. Some tellings have Zeus descend as an eagle himself; others send the eagle Aquila to do the carrying, which is why Aquila still flies nearby in the sky. Once installed as the gods' permanent server, Ganymede was fixed among the stars still pouring, an eternity of the same task that got him abducted in the first place.

The Helix Nebula, hiding in the water jar

Within Aquarius's borders sits one of the closest planetary nebulae to Earth, roughly 650 light years out and popularly nicknamed the Eye of God for its shape in long-exposure imaging. It is the outer layers of a Sun-like star, shed as the star nears the end of its life, expanding outward in a glowing ring around the exposed stellar core. Small telescopes can pick it out, a preview, in miniature, of what the Sun's own outer atmosphere will look like billions of years from now.

When does the Age of Aquarius actually start?

Nobody agrees, and not for lack of trying. The phrase refers to precession slowly walking the vernal equinox point backward through the zodiac constellations, out of Pisces and into Aquarius, a shift measured in the same slow wobble that separates the tropical and sidereal zodiacs. But nailing a start date means choosing a convention first: equal 30-degree arcs, the constellations' actual and uneven borders, and which precision of equinox position to use all give different answers, and astronomers have never adopted one standard among them. Depending on which convention is used, calculations for the equinox's crossing into Aquarius span anywhere from the early twenty-first century to several centuries beyond it. The disagreement is genuine, not a secret someone is withholding.

The jar keeps pouring

Every culture that mapped this stretch of sky read the same thing into it: water, endlessly given, never running out. Ganymede pours it as an eternal chore, GU.LA pours it as an act of a god, and the Helix Nebula, entirely by coincidence, sits inside the same watery jar as a dying star's own outpouring.