Water theory evaporates, but Mars mystery deepens The Sydney Morning Herald

The first close-up pictures of the outcrop of rock discovered by NASA’s Opportunity rover on Mars rule out the possibility that the layered rock was created by volcanic lava flows. The finding makes it much less likely that there was once a large body of water at the Meridiani Planum site. But the photographs revealed a new mystery – small grains of an apparently different material embedded in the layers of stone.