While NASA`s Curiosity Rover has been stealing the headlines, new evidence from another of the space agency`s Mars missions has revealed what appears to be a wet underground environment on the planet.
The new information comes from the Mars Reconnaissance Orbiter. It has been analyzing the Martian surface from high above the planet. One of its targets has been the floor of McLaughlin Crater, a large crater measuring 92 kilometers across and more than 2.2 kilometers deep. Scientists say the crater`s depth appears to have allowed underground water, which otherwise would have stayed hidden, to flow into its center.
"A number of studies have shown rocks exhumed from the subsurface by meteor impact were altered early in Martian history, most likely by hydrothermal fluids," said Joseph Michalski from the Planetary Science Institute, and a lead author of the research. “These fluids trapped in the subsurface could have periodically breached the surface in deep basins such as McLaughlin Crater, possibly carrying clues to subsurface habitability."
The researchers say they have been able to identify carbonate and clay minerals in the layered, flat rocks at the bottom of the crater. These usually only form in the presence of water. They say there is no evidence of any large inflow channels into the crater, suggesting instead there may have been a groundwater-fed lake at its bottom.