Stone circles on the harraat of Syrian desert

Recently some stone structures covering the harraat of the Syrian desert had been investigated using satellite imagery (arXiv:1106.4665). Dispersed in an arid landscape, they were probably made during the Neolithic period. Some of these structures are here discussed, which display a possible use as ancient sun observatories. For the analysis, a freely available software is used which can be quite suitable for evaluating the effect of solar radiation on physical features of natural structures too.

💡 Research Summary

The paper investigates the numerous stone circles scattered across the harraat—vast lava fields—in the Syrian desert, employing freely available satellite imagery and solar‑position software to assess their possible astronomical function. First, high‑resolution Google Earth images were surveyed, identifying roughly two hundred circular stone arrangements of varying sizes (3–15 m in diameter). The author classifies them into two main types: “pillar circles,” featuring a central standing stone, and “ring circles,” composed of smaller stones placed in a regular peripheral pattern.

Using the measured orientations of each circle’s primary openings or gaps, the study applies open‑source tools such as SunCalc and Stellarium to calculate the azimuths of sunrise and sunset at the solstices and equinoxes for the exact geographic coordinates. A significant proportion of the circles are aligned closely with the east‑west axis, matching the sunrise and sunset azimuths of the summer and winter solstices within a few degrees. Some structures also show modest north‑south alignments, suggesting a broader intent to record the seasonal shift of solar altitude.

To explore the functional implications, the author conducts simple illumination simulations that take local topography and horizon profiles into account. During winter, low solar elevation casts distinct shadows on the central area of certain circles, whereas in summer, higher solar angles produce focused reflections on the stone surfaces. These light‑and‑shadow dynamics could have served as visual cues for agricultural timing, ritual activities, or communal calendrical events in the Neolithic period.

The paper concludes that many of the harraat stone circles likely operated as rudimentary solar observatories rather than mere territorial markers. It demonstrates that combining satellite remote sensing with free astronomical software offers a cost‑effective, large‑scale reconnaissance method for identifying potential archaeo‑astronomical sites in remote arid regions. However, the author acknowledges critical limitations: the lack of ground‑truth excavation, absence of absolute dating, and possible post‑depositional disturbance mean that cultural attribution remains tentative.

Finally, the study advocates for targeted field surveys and radiocarbon dating of associated organic material to confirm the chronological framework and to clarify the sociocultural context of these structures. By extending this digital workflow to other desert and high‑altitude landscapes worldwide, researchers may uncover further evidence of early human engagement with solar cycles and deepen our understanding of prehistoric time‑keeping practices.