London, May 21 (ANI): A new study has suggested that a cold, wet Mars may have been just as hospitable to life as a warm one.
According to a report in New Scientist, the study investigated what would happen to various mineral solutions on Mars.
Researchers found that solutions containing certain combinations of sulphur, silicon and other ions stay liquid even down to -28 degree Celsius - a much more plausible temperature for early Mars than one above 0 degrees C.
"The results were a happy surprise," said Ricardo Amils of the Astrobiology Centre in Madrid, Spain. "The concentrations you need are not much higher than seawater," he added.
In the study, Alberto Fairen of NASA's Ames Research Center in Moffett Field, California, used models to determine what would happened to water loaded up with generous helpings of calcium, sodium, silicon, iron and sulphur ions, among others.
The relative concentrations of the ingredients matched mineral compositions sampled by four Mars probes: the Landers Viking 1 and Mars Pathfinder, and the rovers Spirit and Opportunity.
In many cases, the water not only remained liquid at extremely low temperatures, but precipitated minerals as it got colder, including jarosite, haematite and gypsum, which are all present on Mars today.
The study may resolve a conundrum about water on Mars.
Despite much evidence that suggests water was once present on the surface, it has proven virtually impossible to come up with a Martian climate model in which liquid water remains stable for long.
In addition, different carbon dioxide (CO2) levels in Fairen's models make little difference to the results, which suggests that only modest amounts of greenhouse gases may have been required to maintain standing water on ancient Mars.
Significantly, the solutions modeled by Fairen ranged in concentration between 5 and 6 per cent; Earth's seawater, for comparison, has a concentration of 3.5 per cent.
Such concentrations are well within the comfort zone of numerous families of microbes on Earth, which suggests a cold, wet Mars may have been just as hospitable to life as a warm one.
The results could explain the water droplets apparently clinging to and even rolling down the landing struts of the Mars Phoenix Lander in images from the spacecraft. he water is assumed to have come from ice melted by Phoenix's thrusters at the landing site, but it was thought it could only remain liquid on Mars if it contained extremely high concentrations of salt.
"They may not need a lot of salt," said Amils. (ANI)