Astrology, which holds that there is a direct correlation between astronomical phenomena and experiences in the human world, played an integral role in the belief system of the Ancient Egyptians.

Although the advent of astrology has largely been associated with the Babylonians, some historians have argued that they learned their astrological knowledge from the priests of Egypt. Despite this debate, it is clear that the Ancient Egyptian civilization made its own contributions to astrology.

Astrology is often confused with astronomy, and there is in fact an intimate relationship between the two. "Astro-" is the Greek root of "star," and while astronomy is the study and naming of the objects in the sky per se, astrology represents humankind's attempt to impart meaning into the relative positions of those objects.

The ancient Egyptians developed a system of astronomy, as they believed that solar movements could predict natural environmental events such as famine and floods. This system of predicting and drawing connections between human experiences and the cosmos is what has become known as Egyptian astrology.

Although today there is a differentiation between astronomy and astrology, the former being a science, astronomy and astrology were one in the early days of civilization. Astrology now falls under the heading of pseudoscience, meaning that its proponents claim it makes valid predictions rooted in evidence when in fact this has never been shown to be the case.

Early Egyptian astronomers acutely monitored and recorded the movement of the stars such that they would understand their effect on the earth’s environmental changes and the seasons. These astronomers were mainly temple priests, as it was believed that understanding the cosmos was a divine skill.

Temples were constructed to imitate the design of the heavens, the floor being the earth and the arched ceilings imitating the skies. In addition, temple rituals were timed based on planetary activity.

During the Ptolemaic dynasty, Egyptians took the Greek zodiac designations and applied Egyptian Gods to each sign. The ram-headed God Amun was used as a replacement for Aries, and the bull-God Apis, who represented Osiris, was used in place of Taurus. Horus the elder and Horus the child took the place of Gemini.

The goddess Isis was used in place of Virgo, while the Egyptian water God Khum replaced Aquarius. A depiction of the Egyptian zodiac was found on the ceiling of the Temple of Osiris in Denderah.

The main contribution that ancient Egypt astrology made were the units known as decans. Decans are 36 groups of small constellations that rise in order on the horizon every 24 hours. In addition, the Egyptians had devised a calendar of 365 days and broken the year up into 12 months of 30 days each. Astrological signs were attributed to each month and clumped around the four seasons.

Because there were 36 decans that repeated themselves, the period of each decan thus turned out to be the number of days in a year divided by 36 – in other words, about 10 days. But by using exactly 10 days as the period, the Egyptians were left with five days at the end of each year to celebrate. Not so different from what cultures do today, when you think about it!