This piece is part of Mashable Spotlight, which presents in-depth looks at the people, concepts and issues shaping our digital world.
Narrowing her eyes, keen with years of research and experience, Sarah Parcak squints past the dust and sand. Hands out, Egypt's vast landscape at her fingertips, she's searching for clues that will lead her to something extraordinary, buried and missing for thousands of years.
She and her team have been exploring the land for more than a year, looking for a settlement or structure that uncovers the ancient capital of Tanis. No one knows what it looks like, but Parcak has an idea. And she's getting close.
Then suddenly, at the northeast region of the Nile Delta, administrative buildings, streets, palaces and houses of all sizes surface before her eyes. Parcak is excited. She has found Tanis.
But she isn't actually in Egypt — she's thousands of miles away in her lab in Alabama, staring at processed, false color satellite imagery. It's an emerging trend in archaeology that enables people to make extremely important archaeological finds — before excavating the area.
A fellow at National Geographic and an associate professor of anthropology at the University of Alabama at Birmingham, Parcak often tells her students, "A picture is worth a thousand words. A satellite image is worth a million dollars." She's a space archaeologist, part of a growing community of specialists who use satellite imagery and remote sensing technology to find ancient sites once invisible to the naked eye.
Sarah Parcak, Ph.D., zooms in on a satellite image of Egypt. Image: University of Alabama at Birmingham
Often described by media outlets as a modern-day Indiana Jones — "Eat your heart out," she tells Indy — Parcak insists that because this advanced technology can detect multiple sites at once, and even create 3D maps to aid researchers on the ground, the most exciting time to be an archaeologist is right now.
"We have so many thousands of sites to find across the globe, and new techniques to test," she tells Mashable. "The field keeps evolving with the technology, which makes things exciting."
And it's true — space archaeologists like Parcak are quickly reinventing the way we study our past.
To find archaeological traces of Tanis, Egypt’s capital between ca. 1000 - 1400 B.C., she tried combining satellite datasets and running assorted processing techniques to enhance the imagery around the East Nile Delta.
Using near-infrared satellite imagery, which reflects parts of the electromagnetic spectrum the human eye can't see, she tracks subtle changes the Earth's surface density, with different colors corresponding to different densities. Since Egyptians typically built their cities out of mud brick, denser than the soil around it, the satellite imagery revealed what appeared to be diagram of the ancient city.
A filtered image of Tanis, one of Ancient Egypt's most important capitals. Image: University of Alabama at Birmingham
"When the map first appeared, I didn't know what I was looking at, since I had decided to test different techniques on a smaller subset of the imagery, for a faster processing time," Parcak says. "It was only when I applied the same techniques to the entire image that I was able to see the map of the city for the first time."
When she partnered with a French team to excavate and confirm one of the houses she found via satellite, Parcak realized the map was extremely accurate.
"Now, for the first time in 3,000 years, we have a map of one of Egypt’s most important capitals ," she says.
From the phantom outline of a buried city thousands of miles away, Parcak could glean information not only about the layout and structure of Tanis, but also about its ruling class and urban development.
And this only scratched the surface of the technology's potential.
The technology behind space archaeology is, in many ways, similar to the way we use Google Earth. From hundreds of miles in space, you can zoom in to a specific area — whether it's your childhood home or the Great Pyramid of Giza. This is a form of remote sensing: gathering information about an area without physically traveling to it.
But Google Earth is really just a superficial way of observing. With archaeology, remote sensing becomes much more complicated — and fascinating.
"If you look on Google Earth, you have access to a satellite data product; you don't have access to the data," says William Saturno, assistant professor of archaeology at Boston University and former researcher with NASA's Marshall Space Flight Center. "You have access to pictures that have been prepared for you."
In contrast, space archaeologists use different wavelengths of light on images from NASA and commercial high-resolution satellite data to make the unseen become visible, teasing out deeper and subtler information about geology and vegetation on the Earth's surface. That deeper information, according to Saturno, is where the importance lies.
Archaeologist Damian Evans, who heads up the University of Sydney's Cambodian research base, says there's a common misconception that remote sensing technology — specifically LIDAR, or "light radar" — can "see through" vegetation, or that it can penetrate the ground and detect subsurface features.
"What it [really] does is bombard the landscape with so many laser pulses — about a million every four or five seconds, in our case — [that will] hit the ground and return to the sensor attached to the [satellite]," he says.
A satellite collects LIDAR data of the Ganges and Brahmaputra River Basin. Video: NASA/Goddard Space Flight Center
The sensor measures the distance between the satellite and the ground by recording how long it took for the pulse to bounce back from the ground. GPS data allows the sensor to calculate exact coordinates on the ground in 3D.
Researchers end up with billions of points, Evans says, and specialized software can parse them, turning them into elevation models and more.
Remote sensing is especially useful for areas too dangerous for physical exploration or traditional digs. For example, Evans and Saturno used space archaeology to survey Lingapura, the ancient capital of the Angkorian empire in northwestern Cambodia, which Pol Pot and the Khmer Rouge littered with landmines in the 1970s. Evans and Saturno were able to map the area's complex geography.
And Jason Ur, an archaeologist at Harvard University, surveyed Iraq and found what he calls "richest archaeological landscape in the Middle East." In an area with a long history of conflict, Ur and colleagues found approximately 1,200 potential sites through the use of 1960s spy satellites. Traces of elaborate irrigation canals adorn the landscape and snake underground, while previously undiscovered roads and tracks show evidence of ancient transportation. Ur and his team are currently testing their hypothesis that the first residents of this early city planned its construction with great detail.
Space archaeology can even help explain the unexplained. When you see the Polynesian island of Rapa Nui, or Easter Island, it's unmistakable. A total of 887 colossal stone heads and torsos tower over the many green hills and rocky coastlines. Some reach up to 32 feet tall; others are buried up to their necks in the earth.
These iconic moai, each carved in a single quarry on the lower slopes of the island, hold a rich history in their expressions. They are the "living faces" of deified Rapa Nui ancestors, erected to watch over their descendants.
While their purpose may be clear, the real mystery for historians was how the Rapa Nui people moved these monoliths, weighing up to 80 tons, as far as 11 miles away from the quarry. They reached every corner of the island without wheels, cranes or even large animals to help them.
Then in 2012, Carl Lipo from California State University and Terry Hunt from the University of Hawaii used satellite technology to get closer to the truth. From space, they could see prehistoric paths throughout the satellite imagery, suggesting teams of people "walked" the moai into place by pulling them with ropes.
Iconic moai stand on the hill side of the Polynesian island Rapa Nui (Easter Island). Image: Flickr, Nicolas de Camaret
Amid fascinating discoveries, archaeologists also use satellites to track and stop professional looters, who expertly find — and often destroy — unprotected sites and steal important artifacts to sell to collectors and dealers. Within the archaeological community, researchers believe looting is the world's third largest contributor to insurgency and criminal activity, but there are no globally accepted methods to track or curb it.
According to Parcak, looting is especially prevalent in Egypt, Syria and Libya following the Arab Spring in early 2011. But satellite sensing can help.
"I started hearing rumors of site looting in late January 2011, and got high resolution imagery in mid-February," she says. "I could see hundreds of looting pits, and that was at just one site. Now, nearly three years on, we’ve counted nearly 10,000 looting pits and seen a nearly 1,000% increase in total looting."
The estimated value of the items taken from these pits is between $1 billion and $2 billion.
It's easy to identify the looting pits with satellite data, however, since they look nothing like the planned, precise excavation units. Parcak and her colleagues shared their results with Egypt’s antiquities minister, Zahi Hawass, and other members of the Egyptian government to find ways to protect and preserve archaeological sites. This could include crowdsourcing local reports of looting and monitoring sites early on.
"We are losing our past faster than we can map it," Parcak says. "Satellite imagery is the only way we can map the looting patterns effectively."
In March 2001, in the jungles of northeastern Guatemala, Saturno went looking for the rumored location of Maya stelae, beautifully ornamental slabs of stone displaying various figures and hieroglyphs carved in relief. Instead of staying near the Mexican border as planned, Saturno's guides suggested an alternate location: the ancient city of San Bartolo, located farther south.
What Saturno expected to be a simple, day-long trip took 12 hours to get as far as possible by Land Rover, at which point he and his companions traveled another eight hours by foot, using machetes to chop through the dense forest.
As they stood in the middle of what used to be San Bartolo's plaza, now overgrown by thick vegetation, the group realized it had vastly underestimated its needed supplies. The fact overshadowed any accomplishment of reaching the site. Smothered by 90-degree heat and a two-day trip from civilization, they had completely run out of water and food.
They tried everything, from extracting water from vines to searching desperately for collected rainwater, but the group was only able to collect about a half-gallon — not nearly enough for a group of their size.
Tired and dehydrated, carrying upwards of 50 pounds of camera equipment, Saturno ducked into a nearby trench dug by looters to escape the cruel sun. He entered a room buried beneath a Maya pyramid, and after as he switched on his flashlight, he couldn't help but laugh.
There on the walls, at the culmination of his nightmarish trip, Saturno discovered a pristine 2,000-year-old mural.
Archaeologist William Saturno, Ph.D., shows an ancient Maya mural to NASA Deputy Administrator Shana Dale in 2007. Image: NASA/Getty Images
First seeing a figure rendered in magnificent red paint, later identified as the Maya maize god, Saturno's eyes followed images of the figure moving across the room as he entered the underworld. The mural, the oldest that had ever been found, spanned nearly 60 feet in length. Amazed, Saturno photographed the painting without saying anything about it to his guides, wary of who he could trust.
They eventually escaped the jungle alive, taking another full day to return to their vehicles. At that point, the mural left his thoughts; he only wanted to return to his wife and two young children.
Months later, hoping to return to the mural, Saturno worked with Tom Sever, NASA's main archaeologist at the time, and earth scientist Dan Irwin to try to find water in the area using IKONOS satellite data.
"We were going to be running a long-term archaeological project there, and identifying water was going to be an important thing for us to [find], and an easy thing to [find] with satellite imagery," Saturno says. "So long as this high-resolution, commercial data was going to be available, might as well take advantage of it."
Sever and Irwin sent him copies of printouts from IKONOS, and despite the apparent lack of nearby water, Saturno noticed various discolorations next to the silhouette of the architectural site. Wondering if those were additional structures, he returned to the site with GPS and the NASA printouts with coordinates. Saturno confirmed that the discolorations were indeed Maya architecture, verifying four or five structures and hypothesizing the location of six more.
The Peten region of Guatemala, where Saturno and NASA used remote sensing data to locate and interpret the remains of an ancient Maya city. Image: NASA/Getty Images
Saturno wrote to Sever and Irwin about his success matching the images to actual ruins, assuming they had changed the colors on purpose to find structures. However, they had only tried to make the images brighter, and didn't believe Saturno when he first told them. He and his colleagues on the ground collected GPS data, and presented it to Sever and Irwin when they returned to the United Sates.
This began a long-term collaboration between Saturno and Sever, who continue to work together today.
"But it was at that point when I started to really get into the actual analysis portion of it — to go through the processes that you do to manipulate the data, and understanding, in fact, what I was seeing, and why I was seeing it, and why I was seeing it when I was seeing it," he says.
In a way, archaeology and aerial photography run in Parcak's family. When she and her brother were growing up in Bangor, Maine, their grandfather — a retired forestry professor at the University of Maine and one of the pioneers of aerial photographs for forestry — would take them to his office at the engineering firm where he worked.
"He had his aerial photographic equipment there, including a stereoscope, [with which] you can place two aerial photos on top of each other and view them in 3D," she says.
Parcak later learned her grandfather had run covert ops for the CIA, interpreting photographs taken from above Russia.
Those visits to her grandfather’s office would serve as inspiration for Parcak’s career choice later in life, but it was at a party at the very start of her college career when she found her archaeology niche.
The week before classes started at Yale University's Timothy Dwight College, world-famous Egyptologist and professor William Kelly Simpson invited all first-years to take a bus to Katonah, N.Y. and see his estate. He had an incredibly beautiful home — llamas grazed near the grounds, with ample room for the freshman to picnic and get to know each other before the semester began.
Parcak was the only one to accept the offer. She stepped inside Simpson's house and was immediately impressed by his art collection. The husband of John D. Rockefeller's niece, Simpson became a world-renowned art collector, decorating each room with antiques and the walls with Vuillards, Monets and Matisses.
Walking from room to room, Parcak turned a corner and found herself in Simpson's office. Bookcases filled to the brim with Egyptology books stood as high as the 15-foot ceiling, smelling of pipe smoke and eternal knowledge. And suddenly, like a switch being flipped, she knew.
"That's it. I'm done. I want to be an Egyptologist."
As with any discipline involving technology, space archaeology is advancing quickly. Within 35 years, satellite resolution has increased from 180 feet to 1.5 feet, and in 2014, DigitalGlobe will release the WorldView-3 satellite, with a resolution of about 1 foot.
According to Devin White, senior research scientist and team lead for scalable and high performance geocomputation at Oak Ridge National Laboratory, many archaeologists put the impact of geospatial technologies, especially LIDAR, on par with radiocarbon dating.
Advancements in geospatial technology over the past decade, he says, including the acquisition, processing and visualization of remotely sensed data, have been "truly staggering."
"Archaeology has directly benefitted from this quantum leap," he says. "We have gone from a small handful of researchers, working with hard-to-obtain satellite images of questionable utility, to an entire community grappling with ... high quality geospatial data and software that are quickly and constantly evolving."
White is seeing three trends in particular. The first is creating more immersive experiences. Researchers are adopting multi-scale data fusion and visualization to see analytic environments better. Think Oculus Rift and gesture-based navigation. "Archaeologists have been trying to do something like this for years, but I think the technology, and our understanding of how best to use it, are finally starting to converge," he says.
He also sees the emergence of near-real-time mapping, both on the ground and from the air, to guide work and take measurements, which he says will be as indispensable as GPS.
And lastly, he foresees more widespread inclusion of "machine learning," the use of computer systems that can analyze and sift through large piles of noisy data, automatically parsing what's meaningful and useful.
In addition to such advances in technology, Saturno wants archaeologists and researchers to ask increasingly better questions. "There's a limit to what we can see," he says, "but there isn't a limit to what we can ask."
Parcak points to satellite images on site. Image: University of Alabama at Birmingham
Today, Parcak is going back to her previous satellite finds in Egypt, and delving deeper. By studying how the Nile River has changed course, she's trying to see if she can determine how and why these settlements evolved — and she has plenty of data to play with.
In another area of Egypt (she can't reveal exactly where just yet), she's gathered RADAR data via an active sensor that allows her to see beneath the sand, in some cases up to 10 meters deep (unlike LIDAR, which cannot detect subsurface features), and she's very excited to see what may appear. New technology like this can help archaeologists protect sites they didn't even realize exist.
In addition to her current projects, Parcak continues to teach a whole range of anthropology classes at the University of Alabama at Birmingham.
"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," she says.
One of those problems, she explains, is not understanding each other. But history proves that although the world is diverse, we're really not all that different.
"The archaeological record shows us this diversity of experience and belief systems ... and yet has evidence for past peoples being too hungover for work, mother-in-law jokes and complaints made about terrible neighbors," she says.
"Nothing ever changes. That gives me hope for our future, and teaches us that we have much to learn from our ancestors. We haven't evolved as much as we think in 100,000 years."
Image: Flickr, NASA Goddard Space Flight Center