However, very recent photographic evidences from the compact reconnaissance imaging spectrometer for the Mars (CRISM) onboard of the Mars Reconnaissance Orbiter have suggested that the formation of gullies on Mars cannot be explained by theory of flowing water. Below this temperature, water exists as a glacier and above, as steam only.
Thus, in the extreme and uneventful conditions of saturation by mixtures of salts, liquid water can be stable on Mars between 180 K and at least up to 298 K. This is caused by the increased ionic strength that enhances the freezing point depression and boiling point elevation of the solution. In case the water is contaminated with a mixture of these salts, an increased stability is predicted for liquid water down to 180 K and up to at least 298 K. However, a saturated solution of magnesium perchlorate (Mg(ClO 4) 2) renders this temperature range wider from 198 to 296 K, with the triple point being located at 269 K (salt saturation at 13.5 mass % salt).
The triple point of water under this condition is shifted to 269 K with a saturation solubility of 14.4 mass % of the salt. It is shown that under an average atmospheric pressure of 600 Pa, the saturated solution of sodium perchlorate (NaClO 4) is stable in the liquid phase in the temperature range between 240 and 275 K. The effect of different perchlorate salts on the freezing and boiling points of water while considering their saturation solubility under varying ionic conditions is key to this analysis. This is interesting in the light of the discovery of perchlorate, sulphate, sodium, potassium, and calcium ions over the Martian surface. However, salt dissolution can reduce the freezing point and elevate the boiling point of aqueous solutions. Because of the very low atmospheric pressure on Mars, water cannot exist in the liquid form. The analysis considers the atmospheric pressure and temperature conditions prevalent on Mars. The stability of the liquid water phase on Mars has been examined on the basis of fundamental thermodynamic principles.
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