Apparently, Mars is wetter than we previously thought, but we still cannot live on it. As per a new study, liquid freshwater cannot exist for long on the surface of Mars. It either quickly freeze, or it boils away into the atmosphere. However, brines (supersalty water) has much lower freezing points, and it can persist in its liquid form on Mars for longer. There is possible evidence that such liquid existed over the years in the form of dark streaks of the warm planet.
Is the planet able to support water?
In this new study, researchers used data from the atmospheric models, in order to create a new model that predicts where the liquid bines could exist. The model shows that up to 40% of the planet could support liquid surface brines for about 6 hours at a time. This is a fantastic phenomenon; the brines resists about 2% of the year (one year on Mars lasts for 687 Earth days).
The subsurface is also wetter. This suggests that the brines could actually exist during 10% of the year on Mars, at about 3 inches.
However, these brines are not a promise for a living out there. They are probably very cold, with a maximum temperature of -48 degrees Celsius.
According to the new study: “Our results indicate that (meta)stable brines on the Martian surface and its shallow subsurface (a few centimeters deep) are not habitable because their water activities and temperatures fall outside the known tolerances for terrestrial life.”
But there is also some great news, too. These brines cannot support life as we know it here, on Earth, but future Mars missions should be able to investigate them without worrying that they could get contaminated with microbes from Earth. The results reduce some of the risks of exploring the planet, while they also contribute to future work on the habitable conditions on Mars.