Briny Water May Challenge Future Mars Spacecraft Design

RSS

Weather observations by NASA's Curiosity rover support the surprising overnight presence of salt water films in the uppermost soil layers of the mobile spacecraft's Gale Crater landing site within the equatorial belt of the red planet.

The perchlorate salts detected by Curiosity after its Aug. 6, 2012 landing were discovered in the top soil of the planet's northern latitudes as well by NASA's Phoenix mission after a 2008 landing.The dual detection suggests a widespread presence of perchlorates on the planet, a factor to be considered for those planning future Martian surface hardware.

The Curiosity rover, also known as the Mars Science Laboratory, roams Gale Crafter on Mars in this NASA illustration.

The Gale Crater water and temperature observations by Curiosity and described by 25 researchers in the study Transient liquid water and water activity at Gale crater on Mars, published April 13 in the journal Nature Geoscience, are likely too low to support terrestrial organisms. But conditions could be more favorable at higher latitudes where the water vapor content of the atmosphere is greater.

The findings suggest the brine solutions are more abundant than previously assumed and may have implications for the planetary protection strategies followed by the sponsors of future Mars landers as well as the design and operations of spacecraft that must contend with destructive chlorine bearing brines, according to the researchers.

"Conditions near the surface of present-day Mars are hardly favorable for microbial life as we know it," notes the Nature report's lead author, Javier Martin-Torres of the Spanish Research Council and Sweden's  Lulea University of Technology.  "But the possibility for liquid brines on Mars has wider implications for habitability and geological water-related processes,” he adds in a summary of the findings posted by NASA's Jet Propulsion Laboratory.

Spain's contribution to Curiosity, the Rover Environmental Monitoring Station, is attached to the lander's camera mast and provides constant measurements of air pressure, relative humidity, air and ground temperature, wind speeds and ultraviolet radiation levels.

Data trends measured over a full Martian year by REMS support conditions favorable at the equator for the formation of brines in the upper five centimeters of soil during darkness, according to the research. The salty fluid evaporates at sunrise.

Previous research and observations suggested such comings and goings of brines only at colder higher northern and southern latitudes.

The salty water films form as Martian air just above the ground interacts with pore like openings in the soil. As the humidity rises, salts in the soil absorb enough water molecules to dissolve in liquid, a physical process called deliquescence. Perchlorates are especially suited to the process, according to the scientists.

Curiosity is the first of the Martian robot explorers to measure relative humidity in the atmosphere close to the surface as well as ground temperatures throughout the day and night and the planet's changing seasons. The humidity levels at Gale crater range from five percent on summer afternoons to 100 percent during autumn and winter nights.

The salts lower the freezing point of water to contend with the cold temperatures on Mars.

Please or Register to post comments.

What's On Space?

On Space

Blog Archive
We use cookies to improve your website experience. To learn about our use of cookies and how you can manage your cookie settings, please see our Cookie Policy. By continuing to use the website, you consent to our use of cookies.