Serpent Mound and Sunwatch are the big show-stoppers, but lots of Ohioans have mounds practically in their backyards. My dad used to joke that the Adena and Hopewell had some mounds for burial, and some for religious rituals, but the one near our house was where they threw their empty beer bottles.

There’s oyster cairns all over NYs coastal and riparian plains. Not protected or anything, you can go and poke around

Maine, too.

> “[…] archaeologists believe that the mound's creation could have been influenced by two different astronomical events: the light from the supernova that created the Crab Nebula in the year 1054 CE […] The light of the supernova would have been visible for two weeks after it first reached earth, which could even be seen in broad day light.“

I can’t even begin to imagine how humans would have interpreted such an event.

Historical records from the year 1054 are available (and are of course the reason we date the nebula to "1054" rather than "the eleventh century"). You can just go see what people of the time thought.

Wikipedia doesn't quote the records associated with 1054, but does quote the record of a supernova in the year 185:

> In the 2nd year of the epoch Zhongping [中平], the 10th month, on the day Guihai [癸亥] [December 7, Year 185], a 'guest star' appeared in the middle of the Southern Gate [南門] [an asterism consisting of ε Centauri and α Centauri], The size was half a bamboo mat. It displayed various colors, both pleasing and otherwise. It gradually lessened. In the 6th month of the succeeding year it disappeared.

( https://en.wikipedia.org/wiki/SN_185 )

What people thought appears to have been "sometimes there are new stars, but they go away again".

Anyway people transcribing what they wrote thought that. A very great deal of such Chinese history was sketchily paraphrased when copying to newer media.

And it tells us nothing of what people on other continents thought. The null hypothesis would be that it varied.

The null hypothesis for a celestial phenomenon like this is that it was viewed as an omen. But since it is not obviously good or bad and isn't responsive to anything on Earth, you'd expect it to be viewed as support for whatever anyone already believed. Omens that appear during unpopular reigns are bad omens. Omens that appear during popular reigns are good omens.

Throughout different periods, there were cultures in the Americas that found intense spiritual and political significance in astronomy.

> Wikipedia doesn't quote the records associated with 1054

Wait, what? The Wikipedia article on SN 1054 has an extensive discussion of the Chinese records (https://en.wikipedia.org/wiki/SN_1054#Chinese_astronomy), as well as Japanese records and the Arabic account of Ibn Butlan.

My mistake.

"archaeologists believe that the mound's creation could have been influenced by two different astronomical events: the light from the supernova that created the Crab Nebula"

That's a pretty dubious assertion (and I notice that there aren't any references to which archaeologists supposedly believe this), since:

a) I'm pretty sure there aren't any examples of buildings or structures being "influenced" by this or any other historical supernova in any other cultures; and

b) No mention of the supernova of 1006, which was brighter and longer-lasting than the supernova of 1054?

Hat in hand here — I miss read that as BCE…

Indeed. I'm from Indiana, our 4th grade had lots of Indiana history, and talked about the mound builders a lot. We have a small one uphill from our local YMCA. We talked about the local mounds regulary, from here to St. Louis. Seems to be almost a weird sense of local pride.