What is space archeology, anyway?

A pioneer in the field of space archeology explains her field of expertise - and no, it doesn't involve aliens.

'We're able to see so much more of the world now than we ever could'

Sarah Parcak has been using satellite imagery for about 15 years to reveal archeological sites on Earth. (Steve Wood/University of Alabama at Birmingham)

'Space archeology' conjures up a Star Trek-like vision of examining alien civilizations in distant galaxies.

In reality, it's not so much about turning our eyes outward, as delving deep into history, using satellite imagery to reveal ancient sites often hidden to our human eye.

Sarah Parcak is a pioneer in the field, who has literally written the book on the subject: Satellite Remote Sensing for Archeology. The archeologist and professor at the University of Alabama at Birmingham has used the techniques to uncover countless finds such as pyramids and other Egyptian ruins.

Parcak, a National Geographic Fellow, also won the 2016 TED prize, $1-million towards building a crowdsourcing space archeology platform she dubs GlobalXplorer.

Parcak is now applying her knowledge in an attempt to pin down Viking settlements in Newfoundland, and spoke to the CBC while at the Norse archeological dig in Point Rosee, on the province's southwest coast, in August 2016.

Parcak spent three weeks in the summer of 2016 digging at Point Rosee, Newfoundland, following promising imagery that suggested a possible Viking settlement. (Lindsay Bird/CBC)

 This Q&A has been edited and condensed.

The technology itself — how does this work?

With the human eye, there's a lot we can see, but we're restricted to the visible part of the light spectrum. The great thing about satellites is they record information in the part of the light spectrum we can't see: near infrared, middle infrared, thermal infrared, and of course, radar.

And there are so many things on the Earth's surface that we think look one way, visually, but when you process the imagery using the infrared or middle infrared, all of a sudden you see these vibrant colours and signatures showing individual plant species, or particular kinds of rocks, that all look the same to us. That's really the magic of remote sensing. It allows us to manipulate the data, and see things as they actually are. 

Lifting history to the surface of the image, almost?

That's right. What's buried just under the ground affects overlaying vegetation, soil. It can even hold moisture in different ways. Those are things you can only see using different parts of the light spectrum and by processing the imagery.

Do the images that you get back from the satellites look different, when you're comparing Norse, as opposed to something in Egypt?

Everything we do with imagery depends on where we're working, even down to the kinds of imagery that we order. People think oh, you get an image, download it, and process it. That's not the way it works. You typically have to study the landscape where you're going to be working in detail, You have to understand local geology, soils, vegetation, the temporal nature of what you're dealing with — there's wet times of year, there's dry times of year — and that's going to affect how you can interpret your imagery. We do a lot of study before we even begin a project. Even before we study the archeology, you've got to understand the environment if you're going to be analyzing the imagery properly.

You've found how many sites? 

At this point, I've lost track. There are so many sites out there. As human beings, we've been around for 100,000-plus years. And think about all the places we've been and all the cities that we've built over time. We have been everywhere it's possible to be, and even lived in places where today we go, 'how could we have lived there, hundreds of thousands of years ago?' But it just shows you the scale of what's left to find.

The satellite imagery makes information from light spectrums invisible to the human eye, such as infrared, visible, allowing archeologists to spot potential buried finds. (Steve Wood/University of Alabama at Birmingham)

How do you think using that term, 'space archeology', has helped create accessibility to the public?

I think the reason I like using the term 'space archeology' is that it pulls in two things that kids like: space, and archeology. And it kind of gives them a sense of the type of work we do. And I keep having to tell some people, no no no - it's not aliens, turn the cameras the other way.

Do you think it gives a little bit more sense of wonder to the whole field?

I think it does. I think right now, given the state of the world, and the challenges we're facing with government funding, both in Canada and the U.S. and in Europe, anything we can do to engage the public more actively, and get them excited, while still maintaining and honouring the science of what we do is really important. Because ultimately the majority of my funding comes from public sources. 

Do you have any sense of how many people are working in the space archeology field, besides yourself?

When I started doing this work, about 15 years ago, there weren't as many. I'd say definitely in the hundreds now. There were maybe a few dozen people doing it 15 years ago. so the field has definitely grown.

How has space archeology evolved over 15 years?

I think we can say now — I'm very comfortable saying this — it's become much more a standard approach. An archeologist typically wouldn't go into the field, especially if they're doing a survey project, without having done remote sensing work prior to that.

Is there any downside to having so much more of the world mapped and exposed?

Certainly. I suspect that looters are using open source tools like Google Earth. I get images from time to time from very sketchy email accounts, saying 'is this a feature?' and I just wonder. I can't accuse, but it's suggestive that perhaps nefarious individuals are using it. I think like anything, with greater access and information, come greater responsibilities. We're able to see so much more of the world now than we ever could.

A project that I'm working on via the TED prizes, we're about to launch a crowdsourcing platform, a citizen science platform to allow anyone in the world to engage with finding archeological sites. What we're doing is, unlike Google Earth, there's no latitude or longitude information: you're just going to get a small area to look. So there's ways of masking that data, to help protect sites. I think we just need to think a little bit differently. How is it we can use this data in the best possible way to protect archeological sites and enhance heritage, rather than threaten it?

Parcak has used space archeology to great success in her main field of Egyptology, locating buried pyramids and ruins. (National Geographic)

There's a real innate sense of responsibility that goes along with this.

Very much so. The last thing I want to do is publish a paper that shows an area of Egypt that's rich in tombs that says, 'look at where I found all these new tombs!' That would just be the height of irresponsibility on my part. But I can certainly clip and mask the image and say, 'this is an image of a site south of Cairo.' Good luck finding it.

Most people are pretty good, and are interested in history and archeology and want to help. But there is that fraction of a percent element that is looting and damaging sites, and they're happy to get their hands on good data on where sites are. We're trying to be much more responsible.

To watch Reg Sherren's story about the dig by Parcak and her team at Point Rosee, N.L. click on the link below.

Archaeologists are hoping to prove that a second Viking settlement existed in Point Rosee, Newfoundland. 12:31

About the Author

Lindsay Bird

CBC News

Lindsay Bird is a journalist with CBC Newfoundland and Labrador, based in Corner Brook.