The study of the astronomical practices, celestial lore, mythologies, religions and
world-views of all ancient cultures is called archaeoastronomy. It is described, in essence,
as the "anthropology of astronomy", to distinguish it from the "history of astronomy". Many
of the great monuments and ceremonial constructions of early civilizations were
(5)astronomically aligned, and two well-known ancient archaeological sites seem to have had
an astronomical purpose. The Orion mystery, as it is dubbed, purports that the geometry
and brightness of the stars in the Orion constellation are mirrored in the alignment and
size of the great pyramids of Egypt. While this claim remains hypothetical, it is
nevertheless clear that ancient Egyptians incorporated astronomy with architecture. In the
(10)Temple of Abu Simbel, for example, sunlight penetrates a sacred chamber to illuminate a
statue of Ramses on October 18, which ushered in the start of the Egyptian civil year.
Astronomy did not exist on its own, however, but as one limb of a larger body whose other
limbs included agriculture and the after-life. In this sense, astronomy linked the two
themes humans are most obsessed with: life and death.

Around the same period, another monument was erected that combines religion,
architecture and astronomy. Stonehenge was built in three separate stages, starting in
approximately 3000 B.C. Mostly it remains a mystery, but two clues offer some
enlightenment. One is that the megalithic arrangement is not random nor purely aesthetic
but astronomical: It marks the solstice and lunar phases. The other is that archaeological
(20)excavations have revealed it was also used in religious ceremonies. Chinese records
suggest their own astronomical observations dated from the same period; Indian sacred
books point to earlier observations; and Babylonian clay tablets show Chaldean priests
had been observing the sky (including the motion of the visible planets and of eclipses)
shortly thereafter. But the earliest physical vestige of an observatory in fact, lies in
(25)southern Egypt. Surprisingly it is probably not the product of a Semitic (Syrian or
Babylonian) peoples but rather sub-Saharan, as evidenced by analysis of a human
jawbone found on site. The Nabta site is the African equivalent of Stonehenge except it
predates it by some 1,500 years.