NASA Color Trick Was Meant for Mars. Now It's Unveiling Rock Art on Earth

Archaeologist Jon Harman discovered that decorrelation stretch, a NASA image-enhancement technique originally developed in 1978 to analyze Martian landscapes, could reveal hidden details in ancient rock art. After applying the method to photographs of Native American paintings in Baja California, Harman uncovered previously invisible figures and has since used the technique to enhance hundreds of rock art images worldwide.