Sarah Parcak

Scientists use satellites to track weather, map ice sheet melting, detect diseases, show ecosystem change... the list goes on and on. I think nearly every scientific field benefits or could benefit from satellite imagery analysis.

I predict that there are hundreds of thousands, if not millions, of undiscovered ancient sites across the globe. The only way to map them and locate them quickly is from satellites.

We've got to map all of our ancient history before it's gone because, let's face it, if we don't have a common heritage to share, something to get excited about, then what are we living for?

We have so many issues with overpopulation and urbanization and site looting. And this isn't just Egypt. This is everywhere in the world, even in America. So we only have a limited amount of time left before many archaeological sites all over the world are destroyed.

You just pull back for hundreds of miles using the satellite imagery, and all of a sudden this invisible world become visible. You're actually able to see settlements and tombs - and even things like buried pyramids - that you might not otherwise be able to see.

To excavate a pyramid is the dream of every archaeologist.

I think archaeologists are stuck, and we are losing our past at a very rapid rate. Tens of thousands of sites will be lost, and we've only unveiled a tiny percent of the past.

If you really want to be a good archaeologist, you have to understand ancient DNA; you have to understand chemical analysis to figure out the composition of ancient pots. You have to be able to study human remains. You need to be able to do computer processing and, in some cases, computer programming.

Archaeologists gave the military the idea to use aerial photographs for spying and field survey. We are fortunate that the spatial and spectral resolutions of the imagery available to us are so broadly useful for archaeology.

When a wall is slowly covered over by earth, the materials it's made from decay and become part of the soils around and above it, sometimes causing vegetation above and next to the wall to grow faster or slower. Satellite imagery helps archaeologists to pick up these subtle changes.

The only technology that can 'see' beneath the ground is radar imagery. But satellite imagery also allows scientists to map short- and long-term changes to the Earth's surface. Buried archaeological remains affect the overlying vegetation, soils and even water in different ways, depending on the landscapes you're examining.

Archaeologists have used aerial photographs to map archaeological sites since the 1920s, while the use of infrared photography started in the 1960s, and satellite imagery was first used in the 1970s.

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.

Before doing fieldwork in Middle Egypt, I analyzed satellite imagery to determine exactly where I wanted to go. Within three weeks, I found about 70 sites. If I had approached this as a traditional foot survey, it would have taken me three and a half years.

We're using satellites to help map and model cultural features that could never be seen on the ground because they're obscured by modernization, forests, or soil.

When you think about archaeology, archaeology is the only field that allows us to tell the story of 99 percent of our history prior to 3,000 B.C. and writing.

In archaeology, context is everything. Objects allow us to reconstruct the past. Taking artifacts from a temple or an ancient private house is like emptying out a time capsule.

I try to tell a lot of stories to make my students aware that the world is a very cool place with many problems that need solving, and that they all can help solve them.

What these satellites do is they record light radiation that's reflected off the surface of the Earth in different parts of the light spectrum. We use false color imaging to try to tease out these very subtle differences on the ground.

I am honored to receive the TED Prize, but it's not about me; it's about our field - and the thousands of men and women around the world, particularly in the Middle East, who are defending and protecting sites.