Scientists are investigating the process of occurrence of linear landslides on Mars.
Scientists have speculated that the intriguing dark streaks on Mars may not be evidence of liquid water, but some other phenomenon. These long and narrow, repeating slanted structures were first detected in 2011 in images taken by the Mars Reconnaissance Vehicle MRO, which was launched into orbit around the Red Planet by the US Space Agency NASA.
Some researchers believe that such structures may have been formed by streams of salt water, and therefore are indications of a potentially habitable environment. This idea was supported by most NASA scientists after it was announced that hydrated salts were found in these structures thanks to scientific instruments from the Martian Reconnaissance Vehicle.
But liquid water is not the only possible explanation for the origin of such linear oblique structures. Some researchers have suggested that they may have been triggered by the seasonal freezing of carbon dioxide, while others argue that these "lines" are nothing more than avalanches of dry mud and sand.
The new study, which was published Monday, March 20, in the journal Nature Geoscience, argues for the latter hypothesis. A team of researchers led by Frederic Schmidt of the University of Paris-South 11 in France modeled these structures. During this study, it was found that only sunlight can cause landslides. This phenomenon is called "heat creep".
Computer simulations have shown that solar heating destabilizes the material of inclined structures, causing landslides.
“Due to solar insolation in the soil, the temperature rises, and thus the air moves into the porous space of the soil, which in turn destabilizes the grains of sand. This effect is amplified many times over in the presence of shade from boulders,”said Schmidt.