This 5,000-year-old stone cairn in Ireland may contain the world's oldest visual representation of an eclipse. (Michael Fox/Boynevalleytours.com)

An unassuming grass-covered stone mound outside Dublin may be home to the world’s oldest visual representation of a solar eclipse.

The Loughcrew Cairns in County Meath, Ireland, date to approximately 3300 B.C., predating the more well-known structures at Stonehenge, in southern England, by about 1,000 years. The 5,000-year-old Loughcrew structures appear to have served as burial sites for some of the region’s inhabitants during the Neolithic era.

The cairns contain a number of large stones with intricate carvings representing spirals, diamonds and other seemingly abstract shapes. Some researchers who have studied the site believe that the placement of the stones and drawings suggests that, like Stonehenge, the structures were built to reflect various astronomical phenomena, such as solstices and equinoxes.

In 2002, one investigator took this idea even further. Paul Griffin, an “archaeoastronomer” from Ireland, considered the stone carvings and the age of the site against calculations of when solar eclipses may have been visible from the area. Those calculations suggested that a near-total eclipse occurred at the site around 3340 B.C., around the time it was built.

One of the Loughcrew cairns also contains a large stone carving of overlapping concentric circles, which could represent a view of the moon partially occluding the sun during an eclipse.

This 5,000-year-old stone carving in Meath, Ireland, predating Stonehenge by at least 1,000 years, may be the world's oldest surviving depiction of an eclipse. (Michael Fox/Boynevalleytours.com)

In Griffin’s telling, the larger concentric circle to the left represents the moon, while the partially occluded circle immediately adjacent represents the sun. Those circles do indeed bear a striking resemblance to a partial solar eclipse, like the one below.


A partial solar eclipse is seen over the Sudanese capital Khartoum on Nov. 3, 2013. (Ebrahim Hamid/AFP/Getty Images)

Other circles surrounding the pair may represent stars suddenly visible in the sky during the near-total eclipse, while the diamonds to the right could refer to stone pillars elsewhere at the site.

According to Griffin’s calculations, this eclipse would have happened around sunset on a day in the late autumn, or Nov. 30, 3340 B.C. in Universal Time.

Previous archaeologists working at the site had discovered charred human remains from nearly 50 individuals placed beneath a basin immediately in front of the carving, suggesting a monument of great ritual importance — “a possible human sacrifice to ‘save’ the Neolithic 'sky God' (Sun) from dying as it descended to the ‘underworld’ at the horizon, with 15 percent of its surface still ‘eaten away,’ ” Griffin speculates.

Is Griffin’s interpretation correct? It’s impossible to know for sure. The people who created the carvings didn’t leave behind any writings to explain their purpose to curious onlookers 5,000 years in the future.

But Griffin’s explanations were convincing enough for NASA to include his ideas in their roundup of eclipse history. Lunar scientist John Dvorak also included them in his recent book on eclipses, “Mask of the Sun,” although he notes that the meaning of the carvings is “open to debate” and that “no one knows for sure exactly what the concentric circles represent.”

Other experts on astronomy and ancient culture are more skeptical of the Loughcrew eclipse hypothesis. Anthony Aveni, a professor of astronomy and anthropology at Colgate University and author of the book “In the Shadow of the Moon,” said in an email that he sees “no reason to tie [the Loughcrew carvings] in any way to eclipses. In my view you need a written record to imply with any certainty that eclipses are being referenced.

“There’s no evidence I know of to suggest that neolithic people anywhere kept track of eclipse cycles,” he added.

These disagreements are bound to arise when you peer back 5,000 years — there’s little certainty when it comes to the motives and ideas of a culture that far removed from our own, particularly one that had not adopted any sort of written language.

But that mystery is, of course, part of the draw — both of ancient cultures, and of the solar eclipses that we know they would have seen, regardless of whether they commemorated them with carvings or inscriptions.

For those of us in the Unites States, some of that mystery will be on full display in just a few days.