As winter finally turns to spring, we celebrate a variety of holidays associated with the rebirth of light and life after winter’s frigidity. Many of our celebrations are shaped by that magical astronomical moment when day begins to overpower night, a day we called the vernal, or spring, equinox.
Yesterday marked that magic moment, but the condition of the ground and sky may not reveal it. As humans have defined it for thousands of years, the spring, or vernal, equinox is not a meteorological event. Instead, it is astronomical in origin.
Since our dim beginnings, we have looked to the sky to tell us when and what to celebrate. Over the next three weeks, this column will celebrate the celestial origins of our contemporary springtime holidays and the ancient – and modern – myths that surround them.
Long ago, ancient people noticed that the sun moves across the sky in a complete circle once a year. In fact, we divide circles into 360 degrees to mimic the number of days in a year.
On the vernal equinox, the sun crosses an imaginary line in the sky called the celestial equator. Old Sol is moving north as it crosses the line, which corresponds to Earth’s equator as if it were projected on the sky.
We, of course, live north of Earth’s equator. As the sun moves north, it rises higher in our sky. The higher it gets, the more directly its rays beam down on our part of the planet. Winter is the coldest season because the sun shines down on us from a lower angle. Spring is warmer because the sun’s rays shine most directly down on us.
Because the sun rises higher in the sky, it spends more and more time above the horizon each day as the season progresses. Today, day and night are about equal in length. Tomorrow, day will be a few minutes longer than night, and the next day, daylight will be longer still.
That process began in December on the winter solstice, the longer night of the year. Every day thereafter, daylight increased, but we are only beginning to see the effects of it now. Meteorologically speaking, it takes the whole season for the more direct rays of the sun to heat up our part of the atmosphere.
Our forbear looked for signs of spring in the nighttime sky, where the gods lived and exerted their often capricious will on humanity.
The rising of one grand constellation marked the beginning of the season. She is Virgo, the Maiden, who is rising this time of year just as daylight turns to darkness. Look for her as a “Y” shaped collection of stars low in the east. Her brightest star, Spica, is located at the bottom of the stroke of the “Y.”
To the ancient Greeks, Virgo was Persephone, daughter of Demeter, goddess of the corn. To the great anguish of her mother, Persephone was forced to spend half the year in the dark underworld as wife of its dark lord, Hades.
Every year around this time, Persephone is allowed to rise from the underworld back into the heavens, and the goddess of the corn brings spring to Earth to celebrate her daughter’s release from the cold realm of death.
That myth probably originated in an even older story told by the Chaldeans. They associated Virgo with Ishtar, “Queen of the Stars.” Ishtar made the crops grow, and she so loved her job that she did it the year round. Humans never wanted for bread, and a golden age ruled our planet.
Ishtar’s diligence did not please King Winter, who was banished to the great Underworld, never to wield his icy power. One fateful day, Winter kidnapped Ishtar’s husband, Tammuz, and dragged him down into darkness. Ishtar was so distraught that she neglected her work, and King Winter took possession of the fields. Ishtar searched the Underworld until she found her husband, but she was also imprisoned by the dark lord of ice and snow. King Winter threatened to rule the Earth forever.
When the gods saw the starvation and human suffering that resulted, they asked Winter to release the springtime goddess from his icy grasp. A compromise was reached. For part of the year, Ishtar was to neglect her duties in the field, and winter could reign. But in the spring, Ishtar could again rise and resume her ascendancy over the lives of humans.
Watch her rise, denizens of planet Earth. Watch her rise! If the weather we’ve had this winter gets you down, go outside and look at the stars of Virgo, whose rising heralds the rebirth of spring and better days yet to come.
Tom Burns is director of the Perkins Observatory in Delaware.