An international research team led by Suniti Karunatillake (Louisiana State University) has found a spatial association between the presence of sulfur and hydrogen found in martian soil. The work may in turn identify hydrous iron sulfates as key carriers of H2O in bulk martian soil. The gamma-ray spectral signature of hydrogen serves as a possible indicator of water, a primary driver of weathering and life processes on Earth. Data from the Gamma Ray Spectrometer onboard NASA’s Mars Odyssey orbiter was published in Geophysical Research Letters on Nov. 22, 2014.
The study indicates that within the southern latitudes of Mars, sulfur compounds have water-to-sulfur ratios that correspond to hydrated sulfate compounds. The ratios were observed over 80 percent of Mars’ southern hemisphere. Consequently, sulfate compounds, acting as primary contributors of H2O, may also influence modern water-driven processes on Mars. [More at links]