NASA scientists announced today, March 2, 2004, that evidence found by the Opportunity rover suggests water once flowed at its landing site on Mars, Meridiani Planum.
Among the signs of water are the round, BB-sized particles like the ones seen here in a mosaic from the microscopic imager taken at a portion of the rock outcrop near Opportunity, dubbed “Guadalupe.” These spherules are not concentrated at particular layers within the rock, as they would likely be if they originated outside the rock and were deposited onto accumulating layers while the rock was forming. That makes the spherules likely to be concretions that formed from accumulation of minerals coming out of solution inside a porous, water-soaked rock.Image Credit: NASA/JPL/US Geological SurveyComplete Mars Exploration Rover Image Collection