An astronomical event that would have been of great importance to the native people of Ohio around 2,000 years ago is happening tonight and tomorrow, when the moon will align with the largest prehistoric geometric earthworks in the world.

The Hopewell people built what modern people call the Newark Earthworks between 100 BC and 500 AD. On November 27 and 28 the moonrise will align with the structures of the earthworks in what is called a northern minimum moonrise, when the moon is at its lowest rising point. This moon-alignment event won’t occur again for another 18.6 years.

Emmy Beach, the spokeswoman for the Ohio History Connection, told Ancient Origins that experts think the people built it for culture, ceremonial and astronomical functions.

“This weekend the moon will be in perfect alignment with the walls of the Octagon earthworks,” she said. The Octagon is one of three major earthworks still remaining at the Newark site. The Octagon earthworks were specifically designed to showcase the moon. The other two major earthworks at the site will not highlight the moonrise.

The public may view the moon alignments at 6:15 p.m. tonight and 7:15 November 28, 2015, at 125 N. 33rd St, Newark, Ohio.

“Built by prehistoric Hopewell Culture between 100 B.C. and 500 A.D., this architectural wonder of ancient America was part cathedral, part cemetery, and part astronomical observatory,” says a blog at the Ohio History Connection. “The entire Newark Earthworks originally encompassed more than four square miles. Over the years, the growth of the city of Newark destroyed many of the Newark Earthworks, but three major segments survived because of the efforts of interested local citizens.”

A 19th century engraving showing the layout of the Newark Earthworks in Licking County, Ohio (Wikimedia Commons)

Those three segments are:

• The Great Circle Earthworks, which had previously been called the Moundbuilders State Memorial. It is nearly 1,200 feet (366 meters) in diameter and was probably used as a ceremonial site by the builders. The walls around it are 8 feet (2.4 meters) high and it includes a moat 5 feet (1.5 meters) deep. The dimensions at the entrance are even greater.
• The Octagon Earthworks, which enclose 50 acres (20.2 hectares) and have eight walls measuring about 550 feet (168 meters) long and ranging in height from 5 to 6 feet (1.5 to 1.83 meters). Inside the Octagon is a circular embankment enclosing about 20 acres (8 hectares), the blog states. The Octagon Earthworks are now on land owned by the Mound Builder Country Club golf course.
• The Wright Earthworks consist of a fragment of a near-perfect square enclosure 940 to 950 feet long (about 288 meters), enclosing an area of about 20 acres. The builders included a wall that formed a set of parallel embankments. The embankments led up to the square enclosure, inside which was a large oval enclosure.

Some artifacts of the Hopewell Culture, including points, a pipe and an ear spool; these were found near Serpent Mound, another huge earthwork of the Hopewell Culture. (Photo by Heironymous Rowe/Wikimedia Commons)

“While we can never know with any certainty the Hopewell’s purpose in designing the earthworks, one theory is that the Hopewell built these earthworks on such a massive scale for astronomical accuracy—long, straight embankments provide longer slight lines that increase the accuracy of astronomical alignments. In 1982, professors Ray Hively and Robert Horn, of Earlham College in Indiana, discovered that the Hopewell builders aligned these earthworks to the complicated cycle of risings and settings of the moon. They recovered a remarkable wealth of indigenous knowledge relating to geometry and astronomy encoded in the design of these earthworks. The Octagon Earthworks, in particular, are aligned to the four moonrises and four moonsets that mark the limits of a complicated 18.6-year-long cycle.”

The Hopewell Culture flourished in Ohio and other parts of the eastern America from 100 BC. It is unknown what they called themselves, but they are named after Mordecai Hopewell, on whose lands the mounds were excavated in the 1800s. They traded with other peoples, made fine artworks and lived in small villages with houses made of posts, wattle and daub walls and thatched roofs. They raised squash, sunflowers, goosefoot and maygrass among other crops. They hunted game, fished and gathered wild plants too. They fashioned tools, knives and projectile points from obsidian and flint and made hooks and awls from bone. They made fine pottery, including bowls and jars, says an article on Archaeology.org. It is unknown why the culture ended around 400 AD.

The site is Ohio’s official prehistoric monument, is U.S. National Historic Landmark and is being considered as a UNESCO World Heritage site.

Featured image: The remnants of the Octagon Earthworks can still be seen on what is now a golf course in Newark, Ohio. The people of the Hopewell Culture built this structure and others there between 100 BC and 500 AD.  (Photo by Jubileejourney/Wikimedia Commons)

By: Mark Miller