Mars minerals left by groundwater

Stephen Withers
Thursday, 08 March 2007 04:09

Science - Space

Mineral deposits found on Mars by the Opportunity rover were probably due to springs rather than long-evaporated seas, scientists now believe.

A study led by MIT's Jeffrey Andrews-Hanna found the minerals were the result of mineral-rich groundwater that evaporated from the surface. On Earth, similar deposits can be found at Lake Eyre (Australia) and White Sands (USA) where natural basins allow water to flow in and then evaporate.

The deposits found by Opportunity are at one of the few locations on Mars where groundwater would reach the surface and evaporate, providing an explanation for the depth of the deposits in the absence of a basin.

This finding does not rule out the presence of seas or oceans during Mars' early history, but it does provide an explanation for the mineral deposits that squares with observations made from orbit and on the planet's surface.