Magickal Mini-Mystery

One in a series of short puzzles with magickal themes, just for fun.

The Old Astrologer's Secret

Sadly, the old astrologer gazed up at the sky. The stars told him that soon his art would be vilified and many like himself would be put to death for practicing it. A new ideology was dawning; its proponents would attempt to destroy the Knowledge of the celestial bodies and how they influence life on earth.

So the old astrologer set out to preserve the Knowledge for future generations. To keep it safe, he knew he'd have to hide the information about the four elements, the thirteen lunar months, the fifty-two weeks of the solar year, and the two archetypal forces in the universe (masculine and feminine) someplace where antagonists wouldn't recognize it. But he also wanted the Knowledge to be easily accessible to all who sought it.

The old astrologer thought and thought, until finally he came up with a clever solution. He'd hide the Knowledge in plain sight! 

Thousands of years later, this ancient Knowledge is still with us. Nearly everyone in the Western world has touched upon it at one time or another, without realizing it. The secret Knowledge is hidden in millions of homes around the world––probably in yours––where it is available to young and old alike.

QUESTION:  Where did the old astrologer hide the Knowledge of the heavens?