During their 3,000-year reign over the Valley of the Nile, the people of Egypt recorded much of the goings-on in the night sky. They associated most astronomical objects with gods or goddesses, or with the Nile, whose dark waters served as a reflection of the dark night sky.

The planets Mars, Jupiter, and Saturn represented different aspects of Horus. Venus was called the traveling star, since it moves back and forth between morning and evening sky.

Egypt was one of the first cultures to devise a zodiac -- a series of animals along the Sun's path through the sky. Important animals in the zodiac included the hippo and alligator.

Egyptians saw the Milky Way — which is the combined glow of millions of stars — as a series of islands in a great river.

And they drew one of the first zodiacs — a series of animals along the Sun's path across the sky. Of course, the Egyptian sky reflected the creatures common to Egyptian life — including the crocodile, hippopotamus, and scarab beetle — as well as the lion and other animals that populate TODAY'S sky.

The most important Egyptian STAR was Sirius, the brightest star in the night sky. It was known to the Egyptians as Sothis, and it represented Isis.

The Egyptian year began when Sirius first appeared in the morning sky, around the summer solstice — the beginning of the Nile's flood season. In fact, the Egyptians believed that Sirius was responsible for the floods, so it was important to accurately predict the star's return.

One herald of the event was the star Procyon, which preceded Sirius into the morning sky. When skywatchers could see Procyon peeking above the horizon just before sunrise, they knew that Sirius wasn't far behind.

	One of the oldest zodiacs was painted in the temple of Sety I at Dendera.

The year was divided into 12 months, which were split into three 10-day weeks. Five days were added to the end of the year, for a total of 365 days. But the TRUE year is a few hours longer, which is why we have leap years, so the calendar fell out of sync with the seasons. So the Egyptians used TWO calendars — the 365-day calendar, and a ritual calendar that coincided with the appearance of Sirius and the phases of the Moon.

The two calendars overlapped once every 1461 years. This date was considered an omen of good fortune. Ramesses the Second — one of the greatest pharaohs of Egypt — pointed out that he was born just a few years after one such convergence. He wanted his subjects — and his successors — to understand that his greatness was ordained by the stars.

en español