spacetoday.net: Mars "blueberries" contain hematite

Posted: Sat, Mar 20, 2004, 9:11 AM ET (1411 GMT)
Mars 'blueberries' (NASA/JPL)

Small, spherical rocks dubbed "blueberries", found at the Opportunity Mars rover landing site, are rich in hematite, a mineral formed in the presence of water, scientists announced this week. The rocks, which are actually gray and the size of BBs, are too small for the rover to analyze individually, but the rover was able to find a concentration of them in a depression named the "berry bowl" within the crater the rover landed in. Analysis of that concentration shows that the blueberries contained significant amount of hematite compared to surrounding rocks. On Earth, hematite with crystals the size found in the blueberries usually form in the presence of water, providing additional evidence that this region of Mars was once a wet environment. However, the finding does not offer any additional clues regarding if the water was part of a lake or sea, or if it was groundwater that seeped through the rocks from below.