Planetary scientists at the Konkoly Thege Miklos Astronomical Institute have modeled the appearance of salty but liquid water on the surface of Mars.
According to the results, late nights and early mornings during the Martian spring and summer could be ideal times for the process to occur, with conditions being most favorable in the Northern Hemisphere.
One of the main targets of research into the possibilities of extraterrestrial life is the presence of liquid water, which is essential for the life we know. Although our neighboring planet, Mars, had even more water millions of years ago, much of it could escape into space due to weak gravity and the lack of a magnetic shield, or magnetosphere. The rest of the planet’s water resources today are in the form of water vapor and predominantly ice. Due to the cold (average -60 ° C) and very low air pressure prevailing on Mars, even if the surface water melts, it evaporates quickly or sublimes from ice to a gas phase and is unable to remain stable in the liquid state.
However, saline aqueous solutions can be liquid at much lower temperatures. On the surface of Mars, the Phoenix spacecraft and later the Curiosity march also detected various perchlorate salts (e.g., Ca (ClO 4 )2, in the form of calcium perchlorate) that aid in the liquefaction process due to their highly hygroscopic properties.
In doing so, the solid salt absorbs so much water that it becomes a liquid substance. The process is often studied in chemical laboratory conditions, and its knowledge is important, for example, in preserving the quality of food and in agricultural research.
No field experiments have been carried out on Mars so far, so the phenomenon can be studied mainly by computer modeling for the time being.
The European ExoMars program is scheduled to investigate liquefaction on Mars for the first time in 2023. The BABLE experiment of the HABIT ( HabitAbility: Brine Irradiation and Temperature) instrument set ( Brine Observation Transition To Liquid Experiment )): this instrument, in the work of which Hungarian researchers from CSFK also participate, will study the vapor scavenging ability of several salts.
The minimum condition for the appearance of a given saline aqueous solution is to achieve the required temperature and atmospheric humidity values - this is different for each salt.
The magnesium perchlorate and calcium perchlorate studied in the current Hungarian research can be liquid even at very low temperatures, around -70 ° C, if the humidity is high enough.
“I can’t wait for the first results of the ExoMars BOTTLE experiment. I have been modeling the appearance of liquid Martian water for years, and we will learn a lot from the first real Martian experimental results,” says Bernadett Pál, the lead author of an article published in the journal Icarus.
According to the results of Hungarian researchers, an aqueous solution of calcium perchlorate may appear in both hemispheres from spring to late summer, examining a full Martian year. In local Martian time, this is likely from late evening to early morning and is most likely expected around one o’clock in the morning.
Examining the entire planet’s surface, liquefied salts can appear almost anywhere in the northern hemisphere at 30 ° latitude in the late evening, and large basins (Acidalia Planitia and Utopia Planitia) emerge as areas of interest in the early hours of the morning.
It is noteworthy that the ExoMars rover’s planned landing site, the Oxia Planum, could be an ideal location for the appearance of the liquid water phase in both the late evening and early morning hours. In the southern hemisphere, a small amount of liquid water may appear temporarily on the edge of the retracting seasonal ice cap.
Image Credit: NASA
You were reading: A model predicts where and when brines may outcrop on Mars
