Stonehenge functioned as an ancient solar calendar, says archaeologist

Astronomical alignments were built on the design and orientation of Stonehenge — the important monument that dominates a plain in southwest England.

The central axis of the megaliths was — and still is — aligned with mid-summer sunrise and mid-winter sunset, the stones perfectly framing sunrise and sunset when the days were longer. and shorter.

But the monument has long been thought to have been used for ceremonial purposes rather than an accurate way of tracking the days, months and seasons of the year.

However, a new study by Timothy Darvill, a professor of archeology at the University of Bournemouth in the UK, has concluded that Stonehenge served as a solar calendar and he has identified how it might have worked.

Stonehenge is made of two types of stone: larger stones from Sarsen and smaller monoliths of bluestone from Wales. The latter are believed to have been the first to be erected at Stonehenge five thousand years ago, centuries before the larger Sarsen stones, which came from a location much closer to the monument.

A ring of 30 vertical Sarsen stones, supporting 30 horizontal lintels, represent the days within a month. Distinctive stones in the circle mark the start of three 10-day weeks, according to the study.

Twelve of those months would add up to 360, but a group of “triliths” — a structure formed by two large vertical stones that support a third stone placed horizontally on top — were arranged in a horseshoe shape in the center of the site. These represent the extra five days needed to match the 365-day solar year, Darvill said.

Four smaller stones that lay outside the circle in a rectangle were a way to keep track of a leap year, with an extra day every four years.

“Finding a solar calendar represented in the architecture of Stonehenge opens up a new way of seeing the monument as a place for the living,” Darvill said in a press release.

“A place where the time of ceremonies and festivals was connected to the very fabric of the universe and the celestial movements in the heavens.”

However, other experts were not convinced by Darvill’s argument.

“The numbers don’t really add up — why should two vertical columns of a trilith (two large vertical stones supporting a third horizontal stone on top) equal one vertical of the sarsen circle to represent 1 day? And there is selective use of evidence to try to make the numbers fit: some of the stones were left out because they evidently cannot fit,” said Mike Parker Pearson, professor at the Institute of Archeology at University College London and leader of the research project The Stones of Stonehenge, by email.

The starting point for Darvill’s explanation was new research that found that the 30 massive sarsen stones were all sourced from the same area and added during the same construction phase, suggesting they were a single unit.

And while only 17 of the 30 upright stones are in their original positions and 22 of the lintels are missing, archaeological work at the site has suggested that it was not the case that the monument was unfinished, but these massive stones were lost to antiquity.

Although the solar calendar is unfamiliar today, it was used in ancient Egypt and other cultures in the eastern Mediterranean around the same time. It is possible that the builders of Stonehenge were influenced by these people, Darvill said.

Recent discoveries of tombs and artifacts near the stone circle have shown that Stonehenge was not home to an isolated group, but part of a deeply interconnected world.

The findings were published in the journal Antiquity this week.