NASA Technique Reveals Faded Paintings at Angkor Wat

A digital method developed at NASA’s Jet Propulsion Laboratory, called decorrelation stretch, has made invisible murals at the Cambodian temple of Angkor Wat visible. The technique, originally designed to enhance satellite images of Mars, was adapted by retired rock‑art enthusiast Jon Harman, who created a plug‑in for the open‑source ImageJ program. Harman applied the algorithm to photographs of the temple’s central tower, exposing thousands of visitors’ unnoticed images of horseback riders and musical ensembles. Since 2010, the tool has been used at sites in Norway, Egypt, Canada, and Mexico, and has helped locate buried Greek structures and examine mummified tattoos. The method now allows archaeologists to recover and study artwork that had faded beyond recognition, opening new avenues for cultural analysis.