Unexpected mineral discovered on Mars

NASA’s Curiosity rover has discovered an unexpected mineral in a rock sample on Mars, a finding that suggests the red planet hosted explosive volcanoes during its evolution.The Mars Science Laboratory rover, Curiosity, has been exploring sedimentary rocks within Gale Crater since its landing in August 2012.Analysing data from an X-ray diffraction instrument on the rover that identifies minerals, scientists detected significant amounts of a silica mineral called tridymite.