Prehistoric Solar Observatory (Winter Solstice)

[Spomek]

Recently discovered a rock art site that looked to possibly be a Solstice Observatory. Went out on the 20th of December to be there at sunrise on the 21st which is the Winter Solstice.

Many times the horizon over which the sun rises has a saddle or the junction of two ridges the the shaman would look to for the day of the solstice. However, this site has a fairly flat ridge (image 1) so it would be impossible for a person to know view the exact same spot over the years. At this site, the Shaman/medicine man created a sighting point by using a crack in a large rock outcrop, and hammered out what we call cupules after he lined up the sun on the ridge with the crack, probably using stones as markers to create a right angle to the sun (image 2). He then would place stones in these to cupules each year so he sighted the same way. The crack in the rock is a bit diagonal, so he could not sight directly down it.

The third image is what the sun looks like coming over the ridge and sighted between the two stones in the cupules with the top of the crack centered between the stones.

Now the picture isn't exactly accurate because I wasn't going to blind myself, and just put my phone up in front of me at arms length and tried to center it. The sun in this photo is up about half way above the ridge so is at full strength. We took the earlier photos with a better camera at first light. But I think the photo is cool anyway.

This image shows some more cupules without stones in them. These may be for either the Equinox or Summer Solstice.

This is the rock art panel with shadow play that we are trying to work out what it might be telling us about how these Indians understood the sun's cycles.

[daBelgrave]

That is quite interesting. Rather than expend the resources to build a permanent sighting structure, they improvised.