A new study suggests that medieval stone discs found in Ukraine were likely used by Vikings as solar compasses to navigate the seas. According to Discover Magazine, these discs, composed of the mineral pyrophyllite and dating between the 12th and 13th centuries, may have been navigational tools that helped Vikings chart their voyages.
Eight discs were discovered at several archaeological sites in Ukraine. "These disks have been previously interpreted as various items, including calendars, craft tools such as needle sharpeners and polishing stones, as well as components of hand-operated bow drills," the study revealed, according to The Independent.
However, certain features of the discs, such as engravings of rings, lines, and other designs, raised questions about their actual purpose. The discs share similarities with wooden solar compasses found across Europe, including markings characteristic of sundial-compasses.
Researchers compared the pyrophyllite discs with other artifacts identified as navigational instruments used by Vikings. "Through measurements and surface analysis, three stone disks exhibit similarities to the Viking sun compasses, with a limited number of examples found in Greenland and the Baltic Sea region," the study notes.
The discs were most likely local products made in workshops near the city of Ovruch, and the origin of the raw material suggests local manufacturing.
Varangian travelers, known as Vikings who journeyed through what is now Russia and Ukraine during medieval times, would have passed by Kyiv, Listven, and Liubech along a major trade route connecting Scandinavia with the Eastern Roman Empire. This suggests that the spread of Viking-inspired solar compass technology in the region is a possibility. The medieval discs assessed in the study may have been among such tools introduced by the Vikings, as reported by The Independent.
Previous studies theorized that Vikings relied heavily on the sun to navigate when sailing, although their navigation methods are not fully understood. Most signs point toward the Vikings' use of the sun for navigation. The wooden discs contained elements characteristic of sundial-compasses, such as a hole for a gnomon and perimeter notches. The Kyiv and Listven discs feature a central hole that could hold the gnomon, the pointy component of a sundial that casts a shadow when hit with sunlight.
Concentric rings and radial lines were carved into the three discs, further demonstrating the semblance of a compass. The researchers suggest that this could mean concentric rings were not present in early Viking solar compasses but developed in later versions. According to Discover Magazine, the Greenland disc, dated to around the start of the 11th century, does not have concentric rings, while the Wolin disc, dated to the end of the first half of the 11th century, has concentric rings similar to the pyrophyllite discs.
The researchers called for further studies and archaeological experiments to confirm whether these discs had a "practical navigational purpose." Although additional investigations are needed to confirm the role of the pyrophyllite discs, it is possible that Vikings who traveled through the region could have imparted technological knowledge that allowed locals to create the solar compasses.
Old Norse sagas speak of sun stones that could locate the hidden sun when held up to the overcast sky. Scientists showed that using sun stones could have been a viable way of navigating. Polarized light is scattered in the air as it passes through the atmosphere, and a sun stone, possibly calcite or cordierite, would have theoretically acted as a filter that determined the direction of polarized light from the sun.
The Vikings' mastery of the seas allowed them to make voyages by boat. Their successful navigation was due to their crafted navigation tools, such as sun compasses. Consequently, Vikings were no strangers to long-distance journeys, allowing them to travel across four major continents.
This article was written in collaboration with generative AI company Alchemiq