The Octagon Earthworks: A Neolithic Lunar Observatory

Aerial photo by Richard Pirko, 1994 (Youngstown State University)

The Octagon Earthworks were part of an ancient Native American geometric earthworks complex constructed by the so-called Hopewell culture sometime in the first centuries of the modern era (0-500AD). Most of those earthworks have been obliterated by development, but the Octagon Earthworks have been preserved on the site of Moundbuilders Country Club in Newark, Ohio.

In the early 1980s two professors from Earlham University--Ray Hively, a physicist, and Robert Horn, a philosopher--discovered that the Octagon was set up by the Hopewell people to allow tracking complex lunar motions during the moon's 18.61-year precession. For an in-depth look, see: Hopewell Lunar Astronomy: The Octagon Earthworks on this site.

The most impressive of those alignments is the line directly along the main axis of the Octagon, which points to the most northerly rise point of the moon during its 18.61-year cycle. On certain days for a period of about two years during this cycle the moon can be observed to rise directly along the Octagon axis.

As such, this year (2005) and next year (2006) will see a series of moonrises along the Octagon axis, marking what would have been very special days to the native people living here nearly 2000 years ago.

Maximum Moonrises at the Octagon, 2005-2006

datemoonrise timemoonrise azimuth
October 21, 20059:23 PM ET52.6º
October 22, 200510:17 PM ET52.5º
November 18, 20057:05 PM ET52.4º
August 18, 200612:23 AM ET52.6º
August 19, 200601:19 AM ET52.4º
September 14, 200611:13 PM ET52.1º
October 11, 200610:03 PM ET52.3º
November 8, 20067:48 PM ET52.5º
December 5, 20065:30 PM ET52.6º

For an animation of how the upcoming November 18, 2005 moonrise will appear (given an unobstructed horizon and clear weather), click on the following 2.7MB MPG movie:

Coincident with the Oct. 22, 2005 moonrise, archaeologists, Native American storytellers, performers and others put on programs at the Ohio State University campus in Newark, Denison University in Granville and other locations in the area. See: Octagon Hundreds (perhaps 1000) people attended the OSU-Newark program, attesting to the great public interest in these earthworks. Here are some photos from the Oct. 22 event:

Address by Dr. Brad Lepper

Overflow crowd

Address by Dr. Hively

Moonrise menu


Secondary alignment


Ritual landscape of the Raccoon Creek Valley

View along the axis today

The present day view along the axis shown above illustrates how unsuited the earthworks currently are for making astronomical observations, due to numerous tree plantings. In fact, a 2002 Ohio Historical Society (OHS) management planning group set itself a task of working with the club to clear the main axis sightline by August:


Clearly this has not been done in time for the fall 2005 moonrises, and stands little chance of being done for 2006, or ever. The golf course technically just leases the site from the owners, The Ohio Historical Society, but in fact the OHS board is all talk and no follow through and effectively accedes to the country club's priorities and restrictive policies.

The current lease, negotiated in 1997, renews the clause in the 1957 lease concerning the public's right to visit the earthworks:


The "Lessor" being of course the OHS. So the issue boils down to what are "reasonable rules" and who sets them. The original 1922 lease had a slightly different formulation:


Interestingly, from 1938 and forward the "Lessor" disappeared from the formulation of "reasonable rules." Certainly, that has been the appearance in fact--that the golf course calls the shots, generally amounting to a big "unwelcome" mat for earthworks visitors. Unbelievably, in secret and without public input, the 1997 lease was finalized, extending this situation until the year 2078. All signed, sealed and delivered by the OHS:

So basically the cards are stacked against the public's right to visit the earthworks and the OHS is reduced to ineffective (and/or half-hearted) pleading in the face of stonewalling from the country club. Nevertheless, efforts are now underway to induce the golf course management to open the site to the public on the evening of Nov. 18 (see: Octagon For the Oct. 22 event, the club management responded in typical heavy-handed fashion. The management tried to squelch the plan by demanding $25,000 in liability insurance. Program organizers obtained the insurance, but nevertheless the country club management at the last minute cancelled their permission, citing concerns about damage to wet greens due to rain in the preceding days. Despite that claim, the grounds were not soaked at all (the rain didn't amount to much). In fact, there was a members-only party at the course that night--a casino night dubbed "Pow Wow"--and for the 10pm moonrise scores of members were standing on the Observatory Mound, drinking highballs and taking in the view of a beautiful orange moon rising above the trees. Newark police guarded the site to prevent interlopers from entering the grounds, and golf course personnel patrolled the area with flashlights, turning people away. Thus, even though the weather gods smiled on the Octagon that night, the previously solid cloud cover unexpectedly breaking just in time, the people most interested in the earthworks were prevented from being there on the special night. Here is a shot of Venus taken at the end of the Oct. 22 program, showing the miraculously clear sky:

Venus over the OSU-Newark campus, Oct. 22, 2005

Update 11/15/2005: As of now, it looks like the golf club has staved off another attempt by the public to visit the earthworks during a moonrise. The public observance of the Nov. 18 moonrise has been forced to an alternate location in Newark. However, as can be seen by the table of moonrises above, there are a six more aligned moonrises stretching out to December 2006, and thus much more opportunity for publicity and public pressure. Realistically, considering the time of moonrise and phase, there are four chances:

  • September 14, 2006 -- 11:13pm
  • October 11, 2006 -- 10:03pm
  • November 8, 2006 -- 7:48pm
  • December 5, 2006 -- 5:30pm
  • Links:


    04/23/05 Mounds Event Unclear (Newark Advocate)
    05/03/05 OHS Provides access for 'Moonrise' event at Octagon Earthworks in Newark
    05/04/05 Moonrise Celebration Plans Resolved (Newark Advocate)
    05/06/05 Moonrise Events a Blessing for Region (Newark Advocate editorial)
    05/11/05 Reason for Ancient Indian Mounds to be Revealed on October 22 (Earlham College press release)
    08/10/05 Moonrise Growing Brighter (Our Town newspaper)
    10/09/05 The World is Discovering Our Earthworks (Newark Advocate)
    10/16/05 A Mound Moonrise (Newark Advocate)
    10/16/05 Mounds Likely Pilgrimage Destination (Newark Advocate)
    10/16/05 Take time to observe moonrise celebration (Newark Advocate editorial)
    10/17/05 Group Wants Indian Mounds More Accessible (Newark Advocate)
    10/22/05 Rain Puts Damper on Moonrise (Mansfield News)
    10/23/05 Earthworks Day Spreads Lore (Newark Advocate)
    10/24/05 Group to make another request for lunar view (Newark Advocate)
    10/24/05 Moonrise panel gets back to work (Newark Advocate)
    10/25/05 Group asks for another shot at moon view (Newark Advocate)
    10/29/05 Nov. 18 Moonrise Viewing Still Unclear (Newark Advocate)
    11/04/05 Mound moonrise date still undecided (Newark Advocate)
    11/05/05 Club offers alternative date for public access to Earthworks (Newark Advocate)
    11/06/05 OHS boss optimistic about Mounds access
    11/15/05 Moonrise celebration to shed light on theory (Newark Advocate)
    11/19/05 Residents brave cold to watch moonrise (Newark Advocate)
    11/28/05 Ohio Indian Mounds: Hallowed Ground and a Nice Par 3 (New York Times)


    OHS Newark Earthworks Historic Site Management Plan
    Earthworks: virtual explorations of the ancient Ohio valley (University of Cincinnati)
    Hopewell Lunar Astronomy: The Octagon Earthworks

    Woodland Indian creation myth: Earth on Turtle's Back maze at Inniswood Park

    this page by Joe Knapp