The results of Earth-bound lab experiments appear to back up the theory that dark lines on Martian slopes are created by water — though in an otherworldly manner, scientists said Monday.
The results of Earth-bound lab experiments appear to back up the theory that dark lines on Martian slopes are created by water — though in an otherworldly manner, scientists said Monday. A team from France, Britain and the US constructed models and simulated Mars conditions to follow up on a 2015 study which proffered “the strongest evidence yet” for liquid water, a prerequisite for life, on Mars.
That finding had left many scientists scratching their heads as the low pressure of Mars’ atmosphere means that water does not survive long in liquid form. It either boils or freezes. Identifying water on Mars is complicated by our limited understanding of natural processes under conditions so different to those on Earth.
In September 2015, a team reported in the journal Nature Geoscience that curious lines running down slopes on the Martian surface in “summer” may be streaks of super-salty brine. They said they had found evidence in the lines of “hydrated” salt minerals, which require water for their creation, then fade as they cool. For the latest study, researchers took to the lab to try and explain how water could have made the lines.
The team, led by Marion Masse of the University of Nantes in France, included several of the authors of last year’s headline-making study.
They placed a block of ice on a 30-degree plastic slope covered with loose fine-grained sand, and allowed it to melt in a chamber in which Martian pressure and summer temperature was recreated. They repeated the experiment under Earth conditions to compare the processes.
Under Martian pressure, they found, melting ice produced a liquid which boiled vigorously as it flowed downslope and filtered into the sand.
