The Salty Waters of Mars

The ancient waterways of Mars were rich with salt and minerals — was microbial life also part of the alien soup?

The Curiosity rover on Mars has sampled ancient lake deposits from Gale Crater on the Red Planet, showing water which once existed there was dense with salt and minerals. By studying mineral deposits on Mars, researchers hope to better understand the composition of water on the surface of that world in the ancient past. Water, on Earth or on Mars, leaves distinctive chemical traces, and examination of mineral deposits can reveal significant information about long-lost seas.