It is an axiom in business that the more mundane the job, the more grandiose the title. Executives seem to believe that we will feel more resigned to a life of interminably rectifying spreadsheet totals if, upon our desks, there lies a placard with the words “Sheilah Jones – Numerical Adjudicator In Omnia Paratus” etched upon it. Decades of this strategy have rightly caused us in the United States to look skeptically upon job titles that sound too cool to be true, and when somebody walks through the door with the occupational description of “Space Archaeologist” we immediately suspect that there is no earthly way the job could be a tenth as rad as it sounds.
And, yes, if you thought that a space archaeologist might be somebody who scans photos of Mars for signs of ancient Burroughsean civilizations, you might well be disappointed, but when you hear that the job involves taking data from satellite surveys across multiple electromagnetic bands and utilizing them to uncover hidden features of ancient terrestrial societies in a modern day mix of Vash and Indiana Jones, you might be ready to concede that the work of a Space Archaeologist lives up to its cool.
For a decade now, the spokesperson for satellite-based archaeology has been Sarah Parcak (b. 1978), a pun-slinging true child of the Eighties whose deep dives into the detectable chemical signatures of nutrient deprived vegetation alternate with references to The Empire Strikes Back and Raiders of the Lost Ark with the refreshing educational instinct of the born communicator. She has used her techniques to uncover unexpected archaeological features in Iceland, Italy, and Newfoundland in addition to her primary focus of pulling back the veil on the truly astonishing richness still to uncover in Egypt, and is in the forefront of archaeologists using crowdsourcing to sift through the world’s terabytes of visual data in search of promising new clues of humanity’s past.
Blending technical magic with archaeological knowledge, Sarah Parcak has shown the true scale of what space archaeology can accomplish.
Parcak was inspired from multiple directions in her youth, by rented Indiana Jones VHS tapes and more directly by her grandfather Harold Young, a World War II veteran who used aerial photographs to plan his paratroop drop missions, and who transferred those skills to a forestry professorship at the University of Maine, where he was a pioneer in using aerial photography as a key tool in forest management. Parcak’s curiosity about her grandfather’s work led her, as a senior archaeology student at Yale University, to take her first class in remote sensing techniques at a time when using satellite imagery for archaeological purposes was in its barest infancy.
At the time, in the age before Google Earth (2001) and WorldView-1 (2007), the available photographs from space consisted of a mixture of declassified surveillance photographs (like those of the 1959-1972 CORONA program) and various governmental surveys (such as the Landsat program used by Tom Sever to map Mayan sites in the 1980s) with resolutions on the order of eight to thirty meters in the visual range of the electromagnetic spectrum. That very lack of resolution forced Parcak and her fellow satellite pioneers to develop methods to scour large-scale terrestrial features for signs of possible archaeological features beneath. One of the coolest of these (there is that word cool again, but if the brown fedora fits…) is the use of differential vegetation growth and health as an indicator of sub-surface architecture.
Essentially, if you have a large stone wall buried beneath the surface, this will have an impact on the root depth and nutrient access of the plants just above it, which will cause those plants to grow to different heights and give off different chemical signatures than those plants around them, resulting in large-scale vegetative variation that a skilled eye can read as evidence of a promising archaeological site beneath. Likewise, defensive ditches dug centuries ago fill differently than the surrounding earth, providing their own unique nutritive base for plants growing above, giving archaeologists the ability to not only detect when something was added to the earth in the days of antiquity, but when something was systematically removed from it as well.
Parcak used such vegetative signals in coordination with a growing treasury of photographs across multiple eras, seasons, and electromagnetic bands, to weave together composite images, precisely balanced to highlight features that might have been near invisible on any single image, but that appear in stark relief when mixed and amplified by an experienced eye. Employing such technical wizardry, she found a Viking settlement in Skagafjordur, Iceland, an ancient amphitheater in Portus, Italy, and a potential Viking stopover site on Point Rosee, Newfoundland, that represented the furthest extent of westward Viking penetration known at the time.
Each of those finds was a tour de force performance of technical magic married to archaeological knowledge, but it was in Egypt that Parcak showed the true scale of what space archaeology can accomplish. After an exciting warm-up at Tell Tebilla that uncovered an ancient temple wall underneath a modern water treatment plant, she proceeded in 2014 to use imagery of probable looting holes to guide the selection of digging sites that uncovered an astounding 802 tombs at the Middle Kingdom royal city of Lisht. She also used analysis of historic photographs to ascertain the dates of looting, and found that the peak coincided with the 2009 economic recession and 2011 revolution in Egypt, thereby providing important evidence about the fragility of the world’s archaeological heritage in the face of economic and social challenges.
From its low resolution beginnings in the 1980s, space archaeology now has at its disposal unspeakable amounts of high resolution photos across the thermal, visual, and microwave spectra, such that the question has morphed from, “Can I find a few good images in the location I am interested in?” to, “How on Earth am I going to sift through all of this data with just one set of eyes?” In 2015, Parcak took a step towards solving the problem of this embarrassment of riches when she applied for, and won, a one million dollar TED grant to develop the GlobalXplorer program which allows ordinary users at home, after a brief training program, to take actual images from global satellites and evaluate them for likely archaeological features. That program, launched in 2017, has over 96,000 users who have evaluated 17.7 million photographic tiles spread across 100,000 square kilometers and who, in the process, have uncovered 19,000 previously unknown archaeological sites.
Sarah Parcak is an example of the very best of what can happen when a fresh technology, wielded by a conscientious and charismatic figure, breathes across the surface of a well-established discipline, widening the scope of its accomplishments, broadening the spectrum of its appeal, and democratizing the pursuit of its ends to the extent that we can all contribute, each in our small but impassioned way, to the project of knowing our past. Hers is a case of rigor married to innovation in an amalgam that passes the closest scrutiny of the professional while accessibly inspiring a new generation to harness our civilization’s space-borne vision to tell us tales about our long-presumed-lost ancestors.
FURTHER READING: GlobalXplorer has finished its Peru expedition and is gearing up to launch its next campaign covering the archaeology of India, in the near future, so keep checking in (and if you want to start studying up to join the next campaign, here are some neat tutorial videos)! In the meantime, you can enjoy Sarah Parcak’s 2019 Archaeology from Space: How the Future Shapes Our Past. The basic ideas and episodes in it are fascinating and inspiring, though the organizational system and inter-stitched narrative devices of the book made it difficult for me to keep the linear order of developments straight at any given moment which led to quite a bit of flipping around (which might speak more to the general confusion of my brain than the structure of the book), but for how cool the material is, it’s worth a bit of befuddlement here and there. You can also follow Parcak on Twitter at @indyfromspace because OF COURSE that’s the Twitter handle you’d have if you were her.