Ancient Tombs May Have Doubled As Telescopes

By Nola Taylor Redd | June 29, 2016 6:01 pm
Dolmen Pedra da Orca em Gouveia, Portugal

Ancient graves like Dolmen Pedra da Orca in Gouveia, Portugal may have also enhanced the view of stars. (Credit: Vector99/Shutterstock)

Ancient astronomers may have used tombs to probe the heavens.

New research suggests that prehistoric humans may have relied on long dark chambers in igloo-shaped structures known as ‘passage graves’ to see the rising stars. The extended narrow entrances of the graves, which are scattered across Europe, may have amplified a viewer’s night vision, allowing them to detect stars rising at twilight sooner than they would otherwise be able to.

“By using these passage graves, the observer would have sat in complete darkness, with only the opening to the passage grave in front of them showing the part of the sky where the star rises,” Kieran Simcox, an undergraduate student at Nottingham Trent University in England, told Discover by email.

Led by Daniel Brown, also of Nottingham Trent, and Fabio Silva, of the University of Wales Trinity Saint David, Simcox studied passage graves’ potential as astronomical instruments. He presented the results Thursday at the National Astronomy Meeting in England.


A view of several ancient passage graves.a) Dolmen da Orca in Western Iberia, b) the window of visibility from within the the chamber, c) Orca de Santo Tisco in Portugal. (Credit: F. Silva)

“By reducing the background area and focusing on just a small part of the sky, an observer will be able to see a star earlier than had they been outside,” Simcox said.

Revealing Secrets

Ancient cultures across Europe placed their dead within passage graves. The early tombs consisted of single or multiple chambers with a corridor leading to an entrance, and the entire structure was covered with mounds of earth or stone. Some of the tombs feature paintings or engravings tied to their original use. According to Silva and Brown, most passageways date back to the Neolithic period, between 6,000 and 2,000 B.C., though some show continued use during the Bronze Age. Famous examples include Ireland’s Newgrange and Scotland’s Maeshowe.

“They were clearly a widespread phenomena spanning the entire Atlantic coast,” Silva and Brown said by email. Tombs can be found in Spain and Scandinavia, as well as within the United Kingdom. “Different regions had their own traditions and architectural styles, but they are all variations on a theme.”

Coming into Alignment

In most tombs, the inner chambers housed the deceased, while outer courts could have been used for more communal practices, possibly related to funeral rites. According to Silva and Brown, however, scholars have begun to question whether funeral rites were the sole purpose of the outer regions.

“These passage graves exhibit elements suggesting that initiation rituals, also known as rites of passage, might have been conducted within the megalithic chamber,” they said.

Combining this information with a 2013 survey suggesting that many ancient societies taught their initiates esoteric ‘secrets’ related to astronomy observations, the pair decided to investigate the alignments of several passage graves. They identified a tomb in Portugal with a chamber pointing to the sky where Aldebaran rises over the Serra da Estrela mountain range, translated as ‘mountain range of the star.’ Aldebaran, which sits in the eye of the bull constellation Taurus, is one of the brighter stars in the northern hemisphere. According to the scientists, around the time the passage grave was built, the star would rise in late April and early May.


A view of the Serra da Estrela mountain range with Aldebaran rising. (Credit: F. Silva)

“The first seeing of this star would have indicated to the civilization that it was time to move to the mountains, as these civilizations spent the winters on low ground near the river and the summers on higher grounds in the mountain area,” Simcox said.

Trying It Themselves

According to Simcox, while literature suggests that faint stars can be more easily identified in dark chambers such as passage graves, no one has studied the effect. The team plans to measure how much long passageways can help viewers to spot faint stars, determining whether or not the Portugal tomb played a role in revealing the rise of Aldebaran.

“The key idea we are exploring is whether this ‘secret’ might have been communicated or revealed by the visibility of the star at dawn to someone inside the chamber days, if not a full week, ahead of the rest of the community,” Brown and Silva said.

CATEGORIZED UNDER: Space & Physics, top posts
MORE ABOUT: archaeology, stargazing
  • van win

    not only that but when you look through a small hole something changes with your focus.

  • Brian Crawford

    “The first seeing of this star would have indicated to the civilization that it was time to move to the mountains.” Possibly, but I see no evidence for such a bold statement. And the star rises every night for more than half the year, much of that time through the window. How does it mark the season? It would be more convincing if there were a dolmen or natural marker on the ridge, so the precise alignment could be used as an indicator.

    • Small_Businessman

      Because the star doesn’t rise at twilight for more than half of the year. It changes as the Earth orbits the Sun. So it might only rise for a week or two at twilight (depending on how much leeway you give it), then six months later, set at dawn.

  • Carmine007

    It might denote the time of the person’s death, as the star rises at approximately the same time, the same date, each year. this goes on for about 10 thousand years.

  • marcosanthonytoledo

    Why is it always assumed that these were tombs to begin with. Couldn’t be we have reverse astronomical devices first maybe tombs later.

    • OWilson

      Something unique to our “new agers”

      Every unidentified ancient artifact must have a “ritual” purpose.

      No need to explain anything beyond that. On to the next dig.

  • OWilson

    Telescopes of the gods?

    Or just buildings.

    I’m facing southeast. When I look out my window and see Sirius rising, I know to forget about gardening for a few months. :)

  • ajax7

    You might want to read what little that has been found about Mithraism d (the precursor of present day Christianity) There were holes cut in the roof of their Holy caves to observe the stars as they passed and could be seen from different viewing spots in the hall. This religion was mixed with Zoroastrianism and adopted by the Roman soldiers of that area (Afghanistan area) and brought back to Rome. Mithras was born in a stable and later killed he the sacrificial bull while the people ran under the scaffold and were splattered with the blood therefore assuring a good life .It is probable that it spread through parts of Europe.

  • Doc2222

    Tunnel vision.

  • SamSam

    When a child, I learned that if I cupped my hand into a “dark” tube and looked though it at a faint object, I could see the object more clearly, during the day or night.

    I later learned that the tube blocked peripheral and scattered light , allowing the eye’s iris and lens to respond more specifically and effectively to the light coming from the object of interest. The passage with a small window would probably be more effective by allowing the use of both eyes to see (collect) the faint light.
    Planning and the fixed nature of the structure and what it views, indicates an observatory… but for what? Each is different?


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