Evidence of Salt Deposits Found on Mars

The U.S. space agency’s Mars Odyssey spacecraft has found evidence of salt deposits on Mars, pointing to where water once was abundant.

National Aeronautics and Space Administration scientists said such deposits might lead to discoveries of possible past Martian life.

A team led by Mikki Osterloo of the University of Hawaii-Honolulu found approximately 200 places on southern Mars that show spectral characteristics consistent with chloride minerals, NASA said, noting chloride is part of many types of salt. The sites range from about half of a square mile to 25 times that size.

They could come from groundwater reaching the surface in low spots, Osterloo said. “The water would evaporate and leave mineral deposits, which build up over years.

Plotted on a Mars map, the chloride sites appear only in the southern highlands where the most ancient rocks on Mars are located.

Many of the deposits lie in basins with channels leading into them, said Philip Christensen of Arizona State University, the study’s co-author. This is the kind of feature, like salt-pan deposits on Earth, that’s consistent with water flowing in over a long time.

Osterloo and his colleagues report the findings in the journal Science.