A new study has revealed that landslides on Mars during the summer months may be caused by ground salts and melting ice.
Using simulated soil samples from Mars, researchers at the US SETI Institute recreated landslides on Mars on a miniature scale in the laboratory.
Frozen, salted, and chlorinated samples were thawed under temperatures set to repeat the Mars summer, resulting in liquid water and mud.
And on Mars, melting of the ice in regolith, the dusty cover of sediments on the planet’s surface, is due to interactions between salts of chlorine and sulfates. This results in an unstable, fluid-like imbalance that leads to sinkholes and landslides, leaving noticeable dark lines, as observed by NASA.
The study indicates that Mars has a “dynamic and active environment” still evolving, which has implications for future human exploration of the red planet, experts say.
“I am excited about the possibility of microscopic liquid water on Mars in near-surface environments where there is ice and salts. This could revolutionize our perspective on habitability under the surface of Mars today,” said study author and senior researcher at SETI, Dr. Janice Bishop. .
Geologists have discussed the strange behavior of Martian landslides since they were first recognized nearly half a century ago.
It can travel at speeds of up to 360 kilometers per hour (about 220 miles per hour) over flat surfaces.
Previous theories suggested that the flow of liquid debris or dry granular material was the cause of these landslides.
But neither of these theories can explain the seasonal flow characteristics of Mars known as the Repetitive Slope Line (RSL), which are seasonal dark streaks on Mars that gradually extend down the hill in warm seasons, then fade in winter and reappear the following year.
“Martian landslides may include a recurring slope line and other sliding debris,” Dr. Bishop told the British newspaper “Daily Mail”, “but the repeated slope line is the best documented version of these features.”
Several thousand repeated slope lines have been identified in more than 50 steep cliffs, from the equator roughly halfway to the poles.
On Earth, only leaked water is known to have these behaviors, but how they form in the dry Martian environment is still unclear.
“We thought of the repeated slope line as potential effluent flows, but the slopes are very similar to what we expect for dry sand,” said Colin Dundas of the US Geological Survey’s Center for Astrogeology.
Some of the frequent slope lines observed near the Martian equator are often interpreted as associated with larger features called canyons, which resemble valleys on Earth.
Images from NASA’s Mars Exploration Orbiter (MRO) provided images of the repeated slope lines on cliffs facing the Sun, as they continue to emerge and could expand over time.
Previous studies suggested the frequent slope lines were associated with chlorine salts and observed their occurrence in outcrops where high sulfate levels were present.
Source: Daily Mail