Esperance The light-colored material in the center of this exaggerated-color image is a vein called “Esperance.” The chemical data Opportunity collected from this target showed that a large amount of nearly neutral-pH groundwater flowed through it in the past, leaving behind aluminum-rich clay minerals. Of all sites Opportunity visited, this site has the best potential to have supported ancient Martian life. NASA / JPL-Caltech / Cornell / ASU