Prehistory and antiquity

Prehistory

In the French Maritime Alps, in the Vallée des Merveilles (about 100 km [60 miles] north of Nice), are thousands of petroglyphs dating from the Bronze Age (c. 2900–1800 BCE). The culture left images of the objects that concerned it—horned animals, the weapons used to hunt them, and so on. There is one clear image of the Sun—a circle with rays coming from it—and, more controversially, archaeologists have identified two images of the star group known as the Pleiades, represented here perhaps by clusters of small cupules carved into the rock. The sky disk of Nebra, a circular bronze plate with areas of applied gold foil, is much clearer as astronomical imagery. It was found in Saxony-Anhalt, Germany, and dates from about 1600 BCE. Its golden images include the crescent Moon, probably the Sun (or perhaps the full Moon), and a cluster of seven small gold dots that almost certainly do represent the Pleiades.

Astronomical connections are apparent in a number of prehistoric monuments and graves. In several Stone Age cultures, burial chambers often faced east. Stonehenge (c. 3000–1520 BCE) was aligned so that its principal axis coincided with the direction of sunrise on summer solstice. Some other astronomical alignments in Stonehenge, such as with the Moon’s most southerly rising and most northerly setting point, are accepted by many archaeoastronomers. However, most discount some of the more extravagant claims—e.g., that Stonehenge functioned as an eclipse predictor.

That prehistoric people should have noticed and kept track of the Sun and the Moon is not astonishing, but because they lived before writing, the meanings that they attached to celestial events are bound to remain obscure. Some early work in archaeoastronomy was harmed by too great a reliance on conjecture, but methods have greatly improved. Modern archaeoastronomers realize that, with enough stones to work with, one can always find some alignment that is correlated with something celestial. Therefore, one must be careful to perform adequate statistical tests to make sure the alignments are significant and not just accidental.