... Credit: Mars Exploration Rover Mission , JPL , USGS , NASA Explanation: At first glance, this sharp, color close-up gives the strong impression of pebbles strewn over a sandy beach. But the picture is one of the first microscopic images of another planet, captured by the Opportunity rover on its tenth sol on the martian surface at Meridiani Planum . ... Publications with keywords: Mars - Opportunity rover - surface . Publications with words: Mars - Opportunity rover - surface . ...