Changes in the geography of Mars always attract significant scientific and even public attention. A lot of signs of liquid water (and therefore life) is probably one of the main drivers of this interest.
A particularly striking changing feature is the Recurring Slope Lineae (RSL), originally found by the Mars Reconnaissance Orbiter (MRO).
Now scientists at the SETI Institute have a modified theory for where those RSLs could develop – a combination of water ice and salt just below the surface of Mars.
According to the SETI team, led by Senior Research Scientist Janice Bishop, a two-step process is underway to create these RSLs.
First, underground water ice must mix with a combination of chlorine salts and sulfates to create a kind of slurry that destabilizes the regolith in the area.
Then the dry winds and dust storms from Mars take over and blow the destabilized material across the surface of Mars in new patterns.
Krupac Crater also shows the development of RSL. (NASA / JPL / University of Arizona)
This is not the first time that researchers have suggested that chlorine salts may be involved in the development of RSL. As with much good science, this theory has now been further fleshed out by data collected in both field and laboratory experiments.
Unfortunately, the field experiments couldn’t be conducted on Mars itself (at least not yet).
However, there are several places on our home planet that are considered “Martian analogues,” including the Dead Sea in Israel, Salar de Pajonales in the Atacama Desert, and the dry valleys in Antarctica.
The SETI team collected data from some of those locations and noted that surface destabilization has already been observed when salt interacts with gypsum, a type of sulfate.
For this project, the team collected data in the dry valleys, where soil geology and temperature are remarkably similar to those on Mars by the Phoenix lander and MRO.
Field work was then followed by lab work, while the team tested Mars analog regolith using colored indicators that would show how the regolith simulant would react when subjected to the same kind of chemical reactions that took place in Antarctica.
All this data collection resulted in a geological model with sulfates, chlorides and water that can explain the appearance of the RSLs on the surface of Mars.
The model also has implications for the habitability of the underground Mars and how the presence of this slurry could affect every biosphere of the red planet.
Until there are a few more on-site tests, this model will be difficult to prove, but plenty are planned for Mars in the near future.
This article was originally published by Universe Today. Read the original article.