Recurring Slope Lineae are dark flow like features spotted on the surface of the planet Mars in the summer season. The RSL flows are seen to grow during the time period when temperatures rise enough for the salty ice present on the planet to melt. They are also known to disappear in the winter season.

The presence of RSL features on Mars have been seen as indication of water streaks in the planet which sets up the debate for presence of water. The Georgia Institute of Technology has been studying minerals that RSL might leave in their wake so as to determine if there really is any water involved.

After studying 13 RSL sites, out of the 200 that are currently available, using Compact Reconnaissance Imaging Spectrometer for Mars or CRISM the scholars have not yet been able to find any spectral signature tied to water or salts. What they did find instead was signatures of ferric and ferrous minerals at most of the sites.

As per them there is no smoking gun to indicate water even though the flow like features appear to be formed by apparent movement of a fluid that we would like to believe is akin to water. Water or no water, the RSL and Mars as a whole will continue to be the center of many more science experiments and studies in the years to come.