Universities Space Research Association |
Lunar & Planetary Institute | 2020 May 11
Several recent observations of Mars have hinted that it might presently harbor liquid water, a requirement for life as we know it. However, in a new paper in Nature Astronomy, a team of researchers have shown that stable liquids on present-day Mars are not suitable environments for known terrestrial organisms. ...
Due to Mars' low temperatures and extremely dry conditions, should a liquid water droplet be placed on Mars, it would nearly instantaneously either freeze, boil, or evaporate away. That is unless that droplet had dissolved salts in it. Such salt water, or brine, would have a lower freezing temperature and would evaporate at a slower rate than pure liquid water. Because salts are found across Mars, brines could form there. “We saw evidence of brine droplets forming on the strut of the Phoenix lander, where they would have formed under the warmed spacecraft environment”, noted Dr. Germán Martínez, a USRA scientist at the LPI, co-investigator of the Mars 2020 Perseverance rover, and co-author of the study.
Further, some Martian salts can undergo a process called deliquescence. When a salt is at the right temperature and relative humidity, it will take in water from the atmosphere to become a salty liquid. “We've been conducting experiments under Martian simulated conditions at the University of Arkansas for many years now to study these types of reactions. Using what we've learned in the lab, we can predict what will likely happen on Mars,” says Dr. Vincent Chevrier, co-author of the investigation at the University of Arkansas.
The team of researchers used laboratory measurements of Mars-relevant salts along with Martian climate information from both planetary models and spacecraft measurements. They developed a model to predict where, when, and for how long brines are stable on the surface and shallow subsurface of Mars. They found that brine formation from some salts can lead to liquid water over 40% of the Martian surface but only seasonally, during 2% of the Martian year. ...
SwRI scientist modeled Mars climate to understand habitability
Southwest Research Institute | 2020 May 11
Salty water everywhere, nor any drop to drink!
Astronomy | Nature Research | 2020 May 11
Distribution and habitability of (meta)stable brines on present-day Mars ~ Edgard G. Rivera-Valentín et al
- Nature Astronomy (online 11 May 2020) DOI: 10.1038/s41550-020-1080-9