A new research from the University of Texas suggests that the enormous mounds of sand found on Mars’ surface were formed due to wind erosion. It seems that the wind has been one of the key forces that have acted upon the Martian scenery.
Since there are no plate tectonics to cause movement or any liquid water to wear off the soil, the wind remains as the only factor that keeps shaping the planetary landscape.
The sediments on the mounds seem to have been formed by running water 3.7 billions of years ago. The wind carried the soil particles throughout the surface of the planet and sand mounds started to form on the craters. An example would be Gale crater, which is over 3 miles high and it’s comprised of sediments and sedimentary rock.
How the mounds were formed
The research team performed a series of experiments to see how the mounds could be formed. First, they built a miniature 30 centimeters-deep crater, filled with moist sand; then, the structure was set in a wind tunnel and the sand was carefully observed as to where it landed in relation to the crater. A mound in the middle of the crater was formed, it widened and deepened around the edges, a sighting that was determined to be of close resemblance to the mounds found on Mars.
More tests were made through computer simulations in order to determine the exact possibilities of how the wind would affect the dust particles. It is theorized that the deeper layers of sediment were formed as there was water on Mars, but when water ceased to be present, the mounds started to be built by the wind gusts. This presents a strong suggestion that, just like Earth, Mars has undergone an important degree of climatic change.
The mounds were seen for the first time in the 1970’s, and they all resided in the bottom of craters. The theory that these mounds were formed out of wind and dust was present at the time of the finding, but it was in the study led by Mackenzie Day, a graduate of the Jackson School of Geosciences of the University of Texas, that the physics behind the whole process was determined and subsequently tested. By studying the characteristics of over 30 different mounds, researchers were able to find a more solid theoretical standing about the climate change that Mars suffered during its Noachian period.
Source: Discovery