Natural salt may have been present on Mars, the NASA team found, and their discovery could provide evidence of life on Red Planet. The study, published in the Journal of Geophysical Research: Planets, found that natural salts, such as iron, calcium, and magnesium oxalates and acetates, may be widespread in the Martian subterranean areas. These salts are chemical residues of organic compounds. The organic matter and salts on Mars may have been formed by geologic processes or by fossils of ancient microbial life, the NASA statement said.
The findings were determined by laboratory tests and analysis of data from Sample Analysis at Mars (SAM), a portable chemical laboratory inside Curiosity's abdomen.
"Once we determine whether there is live salt concentrated anywhere on Mars, we will want to investigate those regions further, and then look deeper into the area where biodiversity can be best stored," said James MT Lewis, a biochemist at NASA's Goddard Space Aviation in Greenbelt, Maryland.
Without adding further evidence to the idea that there ever was a living thing on Mars, direct access to live salt could also support modern Martian survival, because on Earth, other species could use natural salt, such as oxalate and acetates, for energy, the group said.
While direct identification of natural salt on Mars is difficult to do with metals such as SAM, which burns Martian soil and rocks to extract gases that reflect the formation of these samples, the team proposed another Curiosity tool - Chemistry and Mineralogy tool, or CheMin for short.
This tool can get some natural salt if it is available at sufficient prices. So far, CheMin has not found any salt alive, NASA said.
To determine the shape of the sample, CheMin shot X-rays at it and measured the angle at which the X-rays were separated from the detector.
CAMosity's SAM and CheMin teams will continue to look for signs of natural salt as the rover enters the new region of Mount Sharp in Gale Crater.
In addition, the next European Space Agency's ExoMars rover, equipped to ball up to 6.5 feet, or 2 meters, will carry a Goddard device that will analyze the formation of these deep Martian layers.