NASA's Curiosity rover, while exploring Gale Crater, a vast, dry, ancient lakebed with a rise in the center, discovered sediments containing sulfate salts in its soil. The presence of such salts indicates that once there were salt lakes.
Sulfate salts have been found in sedimentary rocks formed between 3,3 and 3,7 billion years ago. Curiosity analyzed other, older rocks on Mars and found none of these salts.
The researchers believe the sulfate salts are evidence of the evaporation of a crater lake in the arid environment of the Red Planet, and they also believe that sediments that formed later may shed more light on how the Martian surface desiccated in the future.
Source: 3dnews.ru