The world has millions of archaeological sites still waiting to be discovered, many threatened with destruction by conflict, looting, encroachment, and environmental change. If we want to curtail archaeological destruction that’s happening on a global scale by a significant margin, it’s going to take more than the efforts of the planet’s handful of archaeologists. It’s going to require everyone’s help.
That’s why, in January 2017, our founder Sarah Parcak — Egyptologist, National Geographic explorer, 2016 TED Prize winner and Space Archaeologist — launched GlobalXplorerº, our online citizen-science platform that invites anyone around the globe to put on their Indiana Jones hat and help archaeologists find the millions of as-yet uncharted, unprotected sites around the world by logging in and scrutinizing photos of Earth taken from space.
We set to work putting together a team, a platform and — most importantly — a global community of enthusiastic citizen archaeologists, and sent them on GlobalXplorer’s first expedition, to Peru. (More on this next!)
GlobalXplorerº has grown into an army of nearly 70,000 citizen archaeologists from all over the world.
Now, one year and our first expedition later, we have news: GlobalXplorerº has grown into an army of nearly 70,000 citizen archaeologists from all over the world and from all walks of life that together examined 14,620,932 brand-new satellite images of Earth. We’re also getting ready to release the results of the first-ever GXº expedition — to Peru.
We’ll be revealing much more in the days and weeks to come, but at this critical juncture, we at GlobalXplorerº wanted to give you a quick overview of who we are, what we do, and how it all works. Stay tuned, though, because we’ll soon be following this inaugural post with the results of our Peru expedition, exciting innovations going on behind the scenes, and articles with lots more context for why the GlobalXplorerº community’s work is so crucial — plus an announcement of our upcoming expedition, which you won’t want to miss!
Why GlobalXplorerº — and why space archaeology?
We humans have always been curious about the relics of the people who came before us. These everyday objects, structures, artworks and other bits of evidence help us map the trajectory of human cultural development. Archeology does the work of finding, recording, analyzing, and preserving the clues that tell the epic stories of how we got to where we are today — stories full of lessons about humankind’s collective resilience and creativity.
Beyond any romantic Hollywood portrayals, the actual process of archeology is far more arduous. You’re more likely to find an archeologist down on their hands and knees in a dusty pit, painstakingly brushing soil away from objects, centimeter by centimeter. While archaeology traditionally involved long, painstaking processes of identifying potential sites — not to mention gaining permission from relevant authorities to investigate them with excavation, documentation and analysis — some things have changed. In the last few years, the availability and falling cost of satellite imagery have made it possible to identify far more quickly and accurately spots on Earth that have yielded ancient artifacts and stories.
A satellite’s eye view
Using remote sensing to spot archaeological sites — now called “space archeology,” a term coined by NASA — is not entirely new. It took some time to get going due to the high cost of satellite imagery, but in the last four to five years, it’s become more of a standard archaeological practice.
The catch? While satellite imagery has made it possible to search the entire planet for thousands of potential sites — as well as sites being plundered by looting, a large-scale problem that’s destroying archaeological heritage at an alarming rate — the planet doesn’t have anywhere enough experts to process all that information.
The world potentially has millions of undiscovered archaeological sites, but for every possible site out there, there are a limited number of archaeologists. They’re all working as diligently and as quickly as they can, but Earth is just too big a place for them to get it all done on their own!
The power of the crowd
Here’s where citizen archaeologists come in. Technology outstrips human eyeball power to analyze all the raw data now available to us: typically, one person can look at about 20 square kilometers before their eyes give out. This translates to about three or four hours a day before eye fatigue sets in, and details get missed.
“GlobalXplorerº is Indiana Jones meets Google Earth.”
— Wired UK
That’s why the world needs many more people looking at the data. The idea behind GlobalXplorerº is that if we can train citizen scientists to know what to look for, we can rapidly scale up the processing of the raw data. Instead of taking years to search a country for all its potential archaeological sites of interest, we can, in theory, do it in a week. Also, the crowd is wise: 70,000 pairs of eyes are not biased, like one person’s may be. Citizen scientists also look at images without an agenda: they can see with fresh eyes.
How does GlobalXplorerº work?
GlobalXplorerº partners with DigitalGlobe, a company whose fleet of satellites provides the high-resolution Earth imagery that GlobalXplorerº users examine. The images are loaded from DigitalGlobe directly onto the GlobalXplorerº portal as individual 300-by-300–meter tiles, and each logged-in user decides whether they think it is or isn’t a site of archaeological interest (read more here).
Each image must have a minimum of six people voting that the tile may contain a potential site before it’s sent on to the GlobalXplorerº team — and 80% of the users have to agree. The margin of error is surprisingly small, with a success rate of about 90% percent. Sometimes the crowd will point something out that turns out to be a big, stone, modern-built animal pen that looks ancient from above. This happens because modern people still use ancient building techniques, for example. But for the most part, the system works very well.
Sorting, ranking, and ground-truthing
Once a tile has enough positive votes, GlobalXplorerº receives the tile to confirm as a site of potential interest. At our GXº lab in Birmingham, Alabama, our small team of in-house archaeologists made up of Sarah, Chase Childs, and other colleagues ranks the positives into categories — from the clearly big ancient settlements to smaller sites — prioritizing them for further investigation.
It’s a triaging system: even with the positively identified tiles, GlobalXplorerº has to prioritize which of the tens of thousands of sites archaeologists will go and confirm. The positives then go out to our partner local archaeologists in the country we’re working in — typically the region’s experts, or sometimes a government’s ministry of culture — who know the area and the priorities of the government involved. These archaeologists travel to the sites that the GlobalXplorerº community has pinpointed to “ground truth” them — i.e., finding physical evidence of and documenting their location.
After this step, the archeological authorities in the region prioritize those potential sites for further investigation, as time and resources allow. In essence, GlobalXplorerº is creating a data-gathering system, and offering the data as a tool for people in various countries to find and protect their own cultural heritage. We share the data with governments, who decide how to use it to expedite archaeological research. We’re also partnering with governments to develop databases of sites that they can then safeguard.
Who are the GlobalXplorersº?
The GlobalXplorerº citizen science community — we call them Xplorersº, for short — are people from around the world of all ages and walks of life, who are rolling up their sleeves and committing their time and eyes to looking for potential sites of interest on the GlobalXplorerº platform. To date, almost 70,000 people from more than 100 countries have registered to use the platform.
Many are elementary and high school teachers and college professors, who use GlobalXplorer° as a teaching tool about satellite archaeology and archaeological destruction. We also have electrical, mechanical, and software engineers reaching out to us about the platform. Even professional and academic archaeologists have participated, including Donna Yates, one of the foremost authorities on illicit antiquities and the trafficking of cultural property.
“GlobalXplorerº gives kids an interactive way to learn about how satellite imagery can be used to see a better world. We’re advocating for children, especially girls, to be exposed to real-life STEM applications early in their education, in hopes of inspiring them to follow a career path that will lead to the next great scientific discovery.”
— Nancy Coleman, DigitalGlobe
Of the nearly 70,000 GXº Xplorersº, only a select few can claim the title of ‘Superuser’ — those who have viewed and voted on more than 50,000 tiles. These include Sean Kohler, an IT architect who developed his long-standing passion for archaeology as a child, who helped beta test GlobalXplorer°, and Doris Mae Jones, a 90-year-old retired editor who developed a passion for paleontology midway through her career. Fascinated by the parallels that archaeology and paleontology share, she’s viewed tens of thousands of satellite images as a means of keeping herself productive and her mind sharp.
What motivates these citizen scientists to commit to GlobalXplorerº? Our Xplorersº are impassioned by a mission to safeguard our global heritage by harnessing the power of the crowd. They’re excited by the chance to make a difference by analyzing satellite imagery, whether it’s for 15 minutes or an hour-and-a-half a day.
What’s the goal? How will GlobalXplorerº benefit humanity?
Our goal is to map the entire world using remote sensing and the eyes of citizen scientists in just 10 years, and using what the crowd finds to build a database that can then be used to protect and preserve archaeological sites. We’ve already taken the first giant step in what we at GlobalXplorerº envision as the next chapter of archaeology — putting an important part of the process in the hands of global citizens, and in doing so, making all of us stewards of the world’s precious cultural treasures.
With your help, GlobalXplorerº will be a tool to facilitate discovery of all kinds, far into the future — creating a new, inclusive, engaged global archaeological community.
UP NEXT: The results of the first-ever GlobalXplorerº expedition: Peru.