According to new research by scientists at the Arkansas Center for Space and Planetary Sciences, saline water on Mars may not be as widespread as previously thought.
The researchers combined data on brine’s evaporation rate, collected during experiments in the Mars simulation chamber, with a global model of the planet’s weather circulation. The goal is to create planet-wide maps of the most likely saltwater locations.
Such a liquid – a mixture of water and salts – is more resistant to boiling, freezing, and evaporation than pure water. Finding them is important for discovering past or present life on Mars. And also places where people who will eventually go to the planet can look for water.
The scientists considered all of the major phase changes in liquids – freezing, boiling, and evaporation – instead of a single-phase, as was usually done in the past. Then they built maps taking into account all these processes at the same time. Previous studies may have overestimated how long saltwater stays on the surface in the cold, thin, and arid Martian atmosphere. To put it simply, in the past, scientists may have overestimated the stability of saline solutions.
The study found that favorable conditions for stable brines on the planet’s surface are likely to be present in the middle and high northern latitudes and large impact craters in the southern hemisphere, as well as in shallow waters near the equator. At best, saltwater can be stable for up to 12 hours a day, scientists conclude.