By Sid Perkins
Small iron oxide nodules recently found on Mars by NASA’s Opportunity rover could have a geological kinship with similar spherules within certain sandstones of the Southwest, suggest scientists who are analyzing the terrestrial material.
Early this year, scientists announced the discovery of tiny, spherical grains of hematite, a type of iron oxide, in some Martian sediments. Those spherules were dubbed blueberries because their distribution within the sediments reminded one of the scientists of blueberries in a muffin. The hematite blueberries provided one of several lines of evidence that suggest water once flowed on the Red Planet (SN: 3/6/04, p. 147: Red Planet Makes a Splash: Rover finds gush of evidence for past water). Although many of the Martian blueberries examined by NASA’s Opportunity rover were still embedded in rocks, erosion had freed others.