Changes in the geography of Mars always attract significant scientific and even public attention. A hope for signs of liquid water (and therefore life) is probably one of the main driving forces behind this interest.
A particularly striking changing feature is the Recurrent Slope Liniae (RSL) originally found by the Mars Reconnaissance Orbiter (MRO).
Now, scientists at the SETI Institute have a modified theory for where these RSLs might develop – a combination of water ice and salt just below the Martian surface.
According to the SETI team, led by lead researcher Janice Bishop, there is a two-step process that creates these RSLs.
First, groundwater ice must be mixed with a combination of chlorine salts and sulfates to create a type of sludge that destabilizes the local rule.
Then, storms of dry wind and dust from Mars take over, blowing destabilized material into new patterns on the Martian surface.
The Krupac crater also shows the development of RSL. (NASA / JPL / University of Arizona)
This is not the first time researchers have suggested that chlorine salts may be involved in creating RSL. As with many good sciences, this theory has now been further materialized through data collected in both field and laboratory experiments.
Unfortunately, field experiments could not be performed on Mars itself (at least not yet).
However, there are several places on our home planet that are considered “analogues on Mars”, including the Dead Sea of Israel, Salar de Pajonales in the Atacama Desert and the dry valleys of Antarctica.
The SETI team collected data at some of these locations and noted that surface destabilization was already observed when the salt interacted with gypsum, a type of sulfate.
For this project, the team collected data in dry valleys, where geology and soil temperature are remarkably similar to those found on Mars by Phoenix Lander and the MRO.
The fieldwork was then followed by laboratory work, as the team tested Mars’ analog rule using coloring indicators that showed how the regulated simulant would react when subjected to the same type of chemical reactions that took place in Antarctica.
All this data collected led to a geological model involving sulfates, chlorides and water, which may explain the appearance of RSLs seen on the surface of Mars.
The model also has implications for the habitability of the sub-surface of Mars and how the presence of this sludge could affect any biosphere the red planet could have.
Until there are other tests on the ground, this model will be difficult to prove, but there are many planned for Mars in the near future.
This article was originally published by Universe Today. Read the original article.