Scientists may have found the cause of mysterious landslides that occur on the surface of Mars. A team of ten scientists in a recent research published in Science Advances suggest that melting snow and salt present on the red planet might be the cause of the Recurring Slope Lineae, known as RSL.
The research led by J. L. Bishop, senior research scientist at the SETI Institute in California also had nine other members which included M. Yeşilbaş, N. W. Hinman, F. M. Burton, A. J. Englert, J. D. Toner, A. S. McEwen, V. C. Gulick, E. K. Gibson, and C. Koeberl.
According to a press release by SETI, team of scientists studied data collected from High Resolution Imaging Science Experiment (HiRISE) from the Mars Reconnaissance Orbiter (MRO) that showed RSL located on sun-facing slopes continued to appear and/or expand over time.
In previous studies it was thought that RSL is related to chlorine salts and scientists noted their occurrence in regions of high sulfate outcrops. However, the current study widens this observation with a near-surface cryosalt activity model based on field observations and lab experiments. But the exact reason of RSL formation on Mars remains a mystery, scientists mention.
Scientists, who run the Mars analog field investigations on Earthat locations like the Dry Valleys of Antarctica, the Dead Sea in Israel, and Salar de Pajonales in the Atacama Desert, have found that when salts interact with gypsum or water underground, it causes disruptions on the surface, including collapse and landslides. Applying the same logic, the study suggests that the RSL means that the red planet contains natural salts and ice underneath its surface.
In a statement, Bishop said that the research team see the RSL from orbit by the dark streaks they produce on the ground and they tend to always occur on sun-facing slopes, which led geologists to think they were related to melting ice early on. The senior research author further mentioned that the interesting thing is that RSL increases over months following dust storms and then fade away, and they appear to form repeatedly in the same regions. The study also found that many these are forming in the equatorial part of Mars, where there is little ice.
The team also ran experiments replicating the behavior of chlorine salts and sulfates, including gypsum, under low temperatures just like in Mars to demonstrate how interrelated these salts are. Through these experiments, researchers have inferred that maybe the microscale liquid water migrates underground on Mars, transferring water molecules between the sulfates and chlorides.