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Along the river Gambia in Senegal, there are more than a thousand stone circles. The people who placed these stones would have observed how the locations of sunrise and sunset varied over the year.

Mysterious stone arrangements reveal Senegal’s ancient connections to astronomy.

These Ancient Stones Helped Track the Seasons

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Along the river Gambia in Senegal, there are more than a thousand stone circles. The people who placed these stones would have observed how the locations of sunrise and sunset varied over the year.

Mysterious stone arrangements reveal Senegal’s ancient connections to astronomy.

Ancient Worlds

These Ancient Stones Helped Track the SeasonsPublished February 15, 2023NARRATOR: Was there astronomy in Senegal before Islam? Maram would like to know. He may soon discover that his country’s connection with the stars reaches much further back in time than he ever realized. Clues can be found along a vast stretch of the River Gambia, where more than a thousand stone circles have been constructed. They were built over thousands of years, right up until the 16th century. Many human remains and artifacts have been excavated at the sites. Scientific research has mainly focused on the burial practices and rituals of the builders. That is about to change. Maram wants to look at them through the eyes of an astronomer.MARAM KAIRE: The first time I heard about these places, I was just asking myself if we can have the same configuration, the same set up between the sample of Stonehenge and these stone circles here in Senegambia.NARRATOR: They are one of the largest concentrations of megaliths so far recorded in the world. But the stone circles are not well known outside of Senegal, and some of them are difficult to find. There are not many signs showing directions to the sites, and the roads and tracks are like a maze. But the local villagers know exactly where the stone circles are located. Maram is joined by archaeologist Aimé Kantoussan and planetary scientist Marc Buie, who is also curious about humanity’s ancient connections to astronomy. They will look for evidence of astronomical alignments at the sites.MARAM KAIRE: You have some megaliths, there on the right.MARC BUIE: The quest that Maram laid in front of me was to somehow show a different and new aspect to these stone circles than had ever before been realized and, specifically, to say, “Is there a direct connection to astronomical phenomena?”NARRATOR: They will begin their survey at Sine Ngayene, the largest stone circle site. It is inscribed on the World Heritage list as a place of universal value. Neither the local people nor visiting archaeologists know who built these circles.AIMÉ KANTOUSSAN (Archaeologist, Museum of Black Civilizations): There is no connection between the people who build these kind of sites and the people who are living here right now. It’s just like they built this kind of site, used them, and they just disappeared.MARAM KAIRE: Aimé tells us that the circles have marker stones facing east. There is a solitary stone that catches my attention. I think it’s important, because there are other stones nearby that may align with it.MARC BUIE: You are saying this has a special orientation. And I’m measuring this angle here to the second stone, which, according to my calculations, is where the sun sets at the beginning of the summer, at the solstice. So, when I look this direction, I confirm the angle 124 degrees to that rock is where the sun would rise at the beginning of winter. So, when I look this direction, this angle is very, very close to the equinox for the beginning of spring and fall.NARRATOR: The people who placed these stones would have observed how the locations of sunrise and sunset varied over the year. When the sun reached its northernmost point, it was the longest day, the summer solstice; at its southernmost point, the shortest day, the winter solstice. And when the sun rose directly east, the days and nights were equal in length, the equinoxes. By aligning stones to these points, the builders would have been able to track the seasons.

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These Ancient Stones Helped Track the Seasons

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