Polaris, Sirius and the Big Dipper are several key marker stars that were identified by the Ancients and used by them for orientation and timing.

The Pole Star:

The Pole Star helped ancients navigate at night showing them the location of celestial north which is the point in the sky directly above the rotational axis of the Earth. Every 26,000 years celestial north traces out a rough circle called precession, because Earth “wobbles” as it spins, kind of like a top. This precession means that we can date buildings and historical events by identifying which star was the Pole Star for the cultures of the period. Today, the  north celestial pole is marked by Polaris, technically known as Ursae Minoris.

Sirius:

Sirius AKA “Canis Majoris,” is the brightest star in the sky and one of the closest to Earth. It has also been known to be called the “dog star” after the name of its constellation Canis. Sirius was significant for the ancient Egyptians because its heliacal rising brought the message of the rush of water into the Nile and the beginning of the year. The term heliacal rising refers to the appearance of the star in the few minutes before dawn, before the Sun (Helios) rises and obscures the light of the stars. Stars are most easily plotted as they rise and set over the eastern or western horizons.

The Big Dipper:

The Big Dipper is sometimes called the Plough, is close to the Pole Star and points to it. The Big Dipper is always visible at night in the Northern Hemisphere. It never actually sets below the horizon, but circles around the Pole Star like the hands on a clock. It’s path around the Pole Star can actually be used to tell the time at night or the season of the year. The ancient Chinese appreciated this constellation as a time-keeper and pole-pointer as the home of the nine flying stars of classical Feng Shui and the dark god of the north.