Changes in Mars’ geography always attract important scientific and even public attention. A hope for signs of liquid water (and thus life) is probably one of the main drivers behind this interest.
One particularly striking changing feature is the Recurring Slope Lineae (RSL) originally found by the Mars Reconnaissance Orbiter (MRO).
Now scientists from the SETI Institute have a modified theory on where the RSLs can develop – a combination of water ice and salt just below the surface of Mars.
According to the SETI team, led by Janice Bishop, senior research scientist, there is a two-step process that creates these RSLs.
First, underground water ice must be mixed with a combination of chlorine salts and sulfates to create a kind of suspension that destabilizes the regolith in the environment.
Then the dry wind and dust storms of Mars take over and the destabilized material blows in new patterns across the Martian surface.
Krupac Crater also shows RSL development. (NASA / JPL / University of Arizona)
This is not the first time that researchers have suggested that chlorine salts may be involved in the creation of RSL. As with very good science, this theory has now been further expanded by data collected in both field and laboratory experiments.
Unfortunately, the field experiments (at least not yet) could be performed on Mars itself.
However, there are several places on our home planet that are considered “Mars 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 at some of these sites and noted that surface destabilization had already been observed when salt interacted with gypsum, a type of sulfate.
For this project, the team collected data in the dry valleys, where the soil geology and temperature are strikingly similar to those found by Phoenix Lander and MRO on Mars.
Fieldwork was then followed by laboratory work, as the team subjected the analog regolith of Mars to tests with colored indicators to show how the regolith simulant would react when subjects were subjected to the same kind of chemical reactions as in Antarctica.
All this data collection has led to a geological model that includes sulfates, chlorides and water that can explain the appearance of the RSLs on Mars’ surface.
The model also has the implications of the habitability of Mars on the surface and how the presence of this fog could affect the biosphere of the red planet.
Until there are still a few tests in the field, this model will be difficult to prove, but there are many of those planned for Mars soon.
This article was originally published by Universe Today. Read the original article.