For thousands of years, the mummies lay buried beneath the sands of the Atacama Desert, a volcanically active region along the northern Chilean coast with virtually no rainfall.
When the first ones were discovered 100 years ago, archaeologists marveled at the ancient relics, some of them fetuses, their little bodies amazingly intact.
But now the mummies, which are believed to be the oldest on Earth, are melting.
Mariela Santos, curator at the University of Tarapaca museum here, noticed a few years ago that the desiccated skins of a dozen of the mummies were decomposing and turning into a mysterious black ooze.
"I knew the situation was critical and that we'd...