Milky Way
The Milky Way is seen in the sky above a path and huts on Lady Elliot Island located north-east of the town of Bundaberg in Queensland, Australia, June 10, 2015. Reuters/David Gray

Ancient stargazers may have used entrance passages of 6,000-year-old Neolithic tombs as telescopes to enhance visibility of the night sky. This could have been a part of an ancient ritual. The megalithic tombs could have also been used by prehistoric communities for setting their calendar, thousands of years before Galileo. Astronomers believe that the ancient tombs provided a unique window from which the stars could be viewed with unprecedented clarity.

According to University of Wales Trinity Saint David and Nottingham Trent University researchers, standing at the centre of the pitch black tombs, people were able to view even the faintest of stars looking out through the entrance. The team of researchers are currently analysing the old graves in Portugal’s Carregal do Sal. They have found out that 13 of the tombs could have been aligned with the brightest star in the constellation Taurus, Aldebaran.

“This first rising of Aldebaran occurred at the end of April or beginning of May 6,000 years ago, so it would be a very good, very precise calendrical marker for them to know when it was time to move into the higher grounds,” Dr. Fabio Silva of the University of Wales Trinity Saint David told The Guardian.

The star rising may have had a big significance for these ancient communities. It is believed that the appearance of Aldebaran signalled the start of the summer migration and in order to time the first appearance of the star accurately in the season, it was important for those people to detect the stars in twilight.

It is highly possible that more such passage graves throughout the UK and Europe were aligned to bright stars, even Aldebaran. Some of the paintings and rock art inside these tombs could have been interpreted as red stars, like Aldebaran. During construction of these tombs around 4,300–3,700 B.C., the star would have risen exactly within the band of the horizon visible from within all of the entrance passages of tombs at Carregal do Sal between 18–27th of April.

“A good proportion of archaeologists and anthropologists have ignored the sky for too long, but the communities that built these prehistoric structures would have lived under dark skies and would have been inspired by it,” Silva told The Telegraph.

It is also possible that the Neolithic people believed that Aldebaran protected their ancestors or was a heavenly abode of the dead. As burial chambers were thought to be sacred, the tombs could have been used for rites of passage.

“Some, including the well-known examples at Newgrange in Ireland and Bryn-celli-Ddu on Anglesey, seem to have been orientated towards either the sunrise or sunset on the summer or winter solstice. But only about 10 per cent of passage graves seem to have these orientations. It would be wonderful if the proposed research could identify patterns that apply to the other 90 per cent,” Professor of Archaeology at Bournemouth University, Timothy Darvill, said.