Archaeology isn’t always a dirty job.
Sometimes it means sitting at a com-
puter and studying satellite images
one by one to see if they show traces
of long-lost ruins or threats to ancient
sites. National Geographic Fellow Sarah
Parcak, a pioneer of what’s been called
space archaeology, has screened plenty
of those images herself. But she won-
dered if volunteers might be able to help.
In January she launched a crowd-
sourcing experiment that allowed
volunteers to be virtual sleuths in the
archaeologically rich country of Peru.
Dubbed GlobalXplorer, the project was
set up as a game using images from a
company called DigitalGlobe that cov-
ered some hundred thousand square
miles of farms, towns, and countryside.
The response was huge. “We got more
than 45,000 users and 10 million image
views,” Parcak said in April, near the end
of the project. “Which is a little bonkers.”
Identifying signs of looting, encroach-
ment, or a potential discovery involved
a learning curve, I found out. I played
for weeks before I realized that the faint
threads streaking across an occasional
image were power lines and the little
white beans strewn across some fields
could be livestock. I don’t know if I made
any big discoveries in the 15,000 images I
viewed, but other volunteers must have.
“The crowd was really, really good
at finding things,” said Parcak. “In one
small area alone, just north of Lima, the
users found almost 3,000 archaeological
features.” An initial review turned up
very few false positives. The results were
so encouraging that Parcak has plans to
begin surveying another country.
ANCIENT SITES AS
SEEN FROM SPACE
By A. R. Williams
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A GLIMPSE OF WHAT’S NEW AND NEXTFURTHER
These are some of the satellite pictures
that GlobalXplorer volunteers considered.