By: Brittany Yabczanka
This year’s Florida Archaeology Month posters featuring photos by Curt Bowen of Little Salt Spring and Warm Mineral Springs are beautiful. We have learned that the coastline of Florida has changed dramatically, but you may be surprised to learn that the sky we see now is also not quite the same as the one the Paleoindians would have seen when they were living near the springs.
Earth’s axis is not completely stable. It “wobbles” due to a “precession cycle” that completes a rotation about every 26,000 years. This means that what we call the North Star, has not always been the North Star and that the apparent position and movement of all the stars and constellations has changed since the first Floridians got here. We call Polaris our North Star because it stays in the same place all night while the other stars seem to move around it. It is a stationary point that can be used to navigate. In the year 10,000 BC, however, the most stationary point would have been somewhere in the middle of what we call the Hercules constellation. In 7,000 BC, it was between Hercules and Draco, moving closer toward Polaris.
As the Earth moves through its precession cycle the star we think of as the “North Star” changes.
To picture how this affects the night sky, try pointing to a wall. Now imagine the room spinning around your arm. Next, point to a different wall and do the same thing. Everything in the room still stays in the same place, but their movement relative to you changes in appearance based on where you are pointing. Of course, it is actually Earth that rotates, but in this case it is easier to picture the room moving like the sky appears to do throughout the night. This is important because this shift affects which stars are visible, when they are visible, and where they rise and set. For people using the stars for navigational, calendric, and/or spiritual purposes, all of these factors are important.
Using a program called Stellarium (free at Stellarium.org), it is possible to turn back the clock at any location and see what the sky would have looked like. In the location window I entered the GPS coordinates of Little Salt Spring and Warm Mineral Springs. At each location, I then opened the time and date window and adjusted it to reflect when some of the first people would have been at each site. For Little Salt Spring, a wooden stake through an extinct tortoise was found that dates to about 12,000 years ago. I used the year 10,000 BC (Stellarium does not use BC or AD, so it would be written as -10,000) because based on the archaeological evidence it is likely that people were occupying the area at that time. For Warm Mineral Springs, I used the year 7,000 BC because artifacts there have been dated to about 9,000 years ago. For all of the images below I used a date in March so that you can go outside tonight and see how the sky has shifted! All pictures represent March 18th at 8:00 pm, but for different years in the past or in 2014.
The stars over Little Salt Spring 12,000 years ago. No, the dock would not have been there 12,000 years ago….
The stars over Little Salt Spring today.
Looking at the picture of Little Salt Spring (facing NE) 12,000 years ago compared to the one today, the most obvious difference is that the modern one has more sunlight on the horizon. This is because, while the sun’s position in the sky does not change dramatically over time, minor changes in the time of day that it rises and sets do occur. Next, you probably notice that none of the same stars appear from the ancient sky to the modern. It is not because of the time of day, it is because of the precession. If you were able to see through the earth in the modern picture (which you can do by clicking the ground icon in the bottom settings bar when using Stellarium), you would see the same stars that are in the ancient picture, just below the horizon. In a 12,000 year span, Hercules goes from being mostly circumpolar (visible all night, revolving close to the North Pole) to rising late in the night, further East in the sky.
The stars over Warm Mineral Springs 9,000 years ago (Buildings and lawn chairs not included).
The stars over Warm Mineral Springs today.
Warm Mineral Springs (facing NW) has similar differences between ancient and modern as the pictures for Little Salt Spring in terms of sunlight and the change in stars. A good eye can pick out, though, that Polaris (our North Star) is not anywhere near being due North. In fact, it would not even visible all night 9,000 years ago! This means that if the Paleoindians were using the stars for navigation, they would have had to use a different star or group of stars than we use to find North today. Most likely, they would have used a star or group of stars that are part of what we call the Hercules constellation.
While looking at these pictures, it is also important to remember that the stars would not have had the same names and myths that we associate with them today. We primarily use the ancient Greek system, but the Paleoindians obviously would not have done the same. They would have had their own names and stories that were important to them connected with the stars. Do you have any names for stars or groups of stars that are not part of the official catalog? Some cultures focused on the sun (the cycle of which is relatively unchanged). Others, like the Inca used the dark spaces between the stars as constellations. Known Native American star lore, like that of the Lakota and Navajo, have names for only a few stars and they tend to be associated with certain stories.
Unfortunately, there is not yet any archaeological evidence for whether the Paleoindians used the stars for navigational or spiritual purposes. A deer antler found at Little Salt Spring with 28 notches in it could be an intriguing clue. One possibility is that this artifact was used as a way of tracking the lunar cycle, which is 28 days long. Dr. John Gifford, who recently gave a talk about his archaeological work at Little Salt Spring at the University of South Florida, spoke about this possibility during his lecture. The moon’s cycle was important to many cultures all over the world as a way to track time and the seasons, as well as for spiritual reasons. Notably, the moon was used by the Hopewell who measured and used the lunar cycle for planning major events and to track the seasons, and interacted with later Native Floridians.
*Note: Some of the stars visible in Bowen’s photos are there because of the type of lens and effects he used, that I was not able to replicate in Stellarium. Orion, for example, in the Warm Mineral Springs picture, is actually almost directly overhead.
To download Stellarium visit: http://www.stellarium.org/
For more information on Hopewell lunar importance: http://www.youtube.com/watch?v=_OJ1yVs0aQE
Brittany Yabczanka graduated from the University of South Florida in 2012 with her B.A. in Anthropology. She focused on Archaeology and minored in Astronomy, and has since built her own telescope. Brittany currently works at the West Central office of the Florida Public Archaeology Network.