Hydrated silicate minerals on Mars observed by the Mars Reconnaissance Orbiter CRISM instrument

The history of water in Mars The Mars Phoenix mission has sent back images of what — before it melted away — looked like water ice. Meanwhile our knowledge of the planet's distant watery past is being refined by the instruments on-board Mars Reconnaissance Orbiter. The presence of interlayered hydrated silicate (phyllosilicate) minerals on Mars preserves a record of past interactions between liquid water and rocks. The phyllosilicates are restricted to ancient terrains dating from the earliest geologic era of Mars, the Noachian, and previous data suggested that phyllosilicates existed within a relatively narrow range of mineralogy. The latest spectromety data from the Reconnaissance Orbiter are consistent with an ancient Noachian origin for the phyllosilicates — but point to a much more varied mineralogy indicative of active, pervasive hydrologic processes throughout the crust of early Mars, including the surface.