Archaeologists know of only two major artifacts of the pharaoh Khufu, who reigned over Egypt more than 4500 years ago. One is the smallest royal statue yet found — an ivory figurine just three inches tall. The other is at the opposite end of the size scale: the Great Pyramid of Giza, one of the seven wonders of the ancient world. The pyramid was built with the help of a guiding light — a star known as Thuban. At the time, it was the Pole Star. It marked due north in the sky, making it a good tool for laying out a structure. It was also the hub of the sky, with all the other stars appearing to rotate around it — a position that’s held great power for many cultures. Thuban stands due north as the sky gets good and dark right now. It’s directly above today’s Pole Star, Polaris, in Draco, the dragon. It’s not very bright, though, so it’s hard to see from light-polluted cities. Thuban lost its position as the north celestial pole because of an effect known as precession. Earth wobbles on it
