The Battle of the Lion and the Bull

In mid-northern latitudes, if you go outside just after dark in April you would notice that Leo the lion is overhead, dominating the sky, and Taurus the bull is setting in the west. This scene was very significant to our ancestors, though for them, this scene took place just after dark at this time. For them, these two constellations in this position it meant that ploughing and sowing could begin. The battle of the lion and bull were symbolic of the changing seasons.

Scenes of heavenly battles between lions and bulls date back to at least 3000BC. Archeologists have found a Sumerian goblet dated to 3000BC which depicts a lion killing a bull. An older depiction was found on an Elamite seal from the fourth millennium BC. More recently, such a battle was found on a Persian miniature painted around the thirteenth century AD. That's five thousand years of this celestial battle.

Let's first examine the skies of 4000BC. At the start of night in early February, Leo dominates the overhead sky. Taurus the bull is sinking below the western horizon, about to follow the Sun into the land of the dead (astronomically meaning that Taurus was approaching a helical setting.) In the days that followed, Taurus could not be seen at all because it was lost in the glare of the Sun (in conjunction.) About forty days later however, Taurus is reborn. The bull comes back to life at dawn, resurrected in the helical rising in the morning sky. This took place at the vernal (spring) equinox, traditionally the time of the rebirth of life in the ancient Near East.

But during that five thousand year reign of the lion and bull depiction, the night sky changed due to precession. Precession is a slow change in the direction that the Earth's axis appears to point to in the sky. To understand it, think of the Earth, spinning as a top with the axis running up through the middle of the top. As a top spins, it also wobbles, Earth's axis sweeps out a circle, taking 26,000 years to do so. The end result is that the axis does not always point at the north star, Polaris. The other constellations appear to shift their positions as well. In 4000 BC, the axis was pointing towards Thuban in Draco.

Because of precession, by 500 AD, Taurus and Leo were no longer in those positions at sunset in early February. Rather, they could be found in this position closer to the vernal equinox in March. The depiction was still very popular though and was just thought to represent the killing of winter (Taurus) and the domination of spring (Leo.) That is why we still think of Leo as heralding spring.

Precession has continued to change our skies and now you must wait until April to catch the bull dying at sunset. The cycles and rhythms of the skies were so important to our ancestors because it represented the cycles of life itself. Today, many people take the skies for granted and have forgotten the role they played. Take a moment and try to see them through our ancestors eyes and ponder this dark sky legacy.

Constellations

The Solar System