An article published in the journal “Nature Geoscience” describes a research in which a team of researchers argues that the signs of liquid water flows found on Mars are actually made up of dry sand. The possible existence of what are technically called RSLs (recurring slope lineae), streaks of sand washed by liquid water, was announced in September 2015 by NASA. A new study of data collected by NASA’s MRO (Mars Reconnaissance Orbiter) space probe may, however, show a different situation.