Archeology from space - Sarah Parcak

When I was a child growing up in Maine, one of my favorite things to do was to look for sand dollars on the seashores of Maine because my parents told me it would bring me luck. But you know, these shells, they're hard to find; they're covered in sand, they're difficult to see.

However, over time, I got used to looking for them. I started seeing shapes and patterns that helped me to collect them. This grew into a passion for finding things, a love for the past in archaeology. Eventually, when I started studying Egyptology, I realized that seeing with my naked eyes alone wasn't enough. Because, all of a sudden, in Egypt, my beach had grown from a tiny one in Maine to one 800 meters long next to the Nile, and my sand dollars had grown to the size of cities.

This is really what brought me to using satellite imagery for trying to map the past. I knew that I had to see differently, so I want to show you an example of how we see differently using the infrared. This is a site located in the eastern Egyptian Delta called Mendy's. The site visibly appears brown, but when we use the infrared and we process it, all of a sudden, using false color, the site appears as bright pink.

What you are seeing are the actual chemical changes to the landscape caused by the building materials and activities of the ancient Egyptians. What I want to share with you today is how we've used satellite data to find an ancient Egyptian city called Itawi, missing for thousands of years. Itawi was ancient Egypt's capital for over 400 years, at a period of time called the Middle Kingdom, about 4,000 years ago.

The site is located in the fjume of Egypt, and the site's really important because, in the Middle Kingdom, this was this great Renaissance for ancient Egyptian art, architecture, and religion. Egyptologists have always known the site of Itawi was located somewhere near the pyramids of the two kings who built it, indicated within the red circles here, but somewhere within this massive floodplain.

This area is huge—it's 4 miles by 3 miles in size. Now, the Nile used to flow right next to the city of Itawi, and as it shifted, changed, and moved over time to the east, it covered over the city. So how do you find a buried city in a vast landscape? Finding it randomly would be the equivalent of locating a needle in a haystack, blindfolded, wearing baseball mitts.

So what we did is we used NASA topography data to map out the landscape, very subtle changes. We started to be able to see where the Nile used to flow, which you can see in more detail. Even more interesting, this very slight raised area seen within the circle appeared, which we thought could possibly be the location of the city of Itawi.

So, we collaborated with Egyptian scientists to do coring work, which you see here. When I say coring, it's like ice coring, but instead of layers of climate change, you're looking for layers of human occupation. At 5 meters down, underneath a thick layer of mud, we found a dense layer of pottery.

What this shows is that at this possible location, 5 meters down, we have a layer of occupation for several hundred years, dating to the Middle Kingdom, dating to the exact period of time we think Itawi is. We also found worked stone, carnelian, quartz, and agat. This shows that there was a jeweler's workshop here. These might not look like much, but when you think about the most common stones used in jewelry from the Middle Kingdom, these are the stones that were used.

So, we have a dense layer of occupation dating to the Middle Kingdom at this site. We also have evidence of an elite jeweler's workshop, showing that whatever was there was a very important city. No, Itawi was here yet, but we're going to be returning to the site in the near future to map it out. Even more importantly, we have funding to train young Egyptians in the use of satellite technology so that they can be the ones making great discoveries as well.

I wanted to end with my favorite quote from the Middle Kingdom, probably written at the city of Itawi 4,000 years ago: "Sharing knowledge is the greatest of all callings. There's nothing like it in the land." So as it turns out, TED was not founded in 1984 AD, making ideas happen; it actually started in 1984 BC at a now-lost, long city found from above.

It certainly puts finding seashells by the seashore in perspective. Thank you very much.