The geological properties of Mars include the martian soil, which is the outermost layer of fine regolith that covers the planet's surface. The Martian soil is being studied by scientists to extract a large amount of information about the planet. An attempt is also made to learn about the future possibility of living on Mars.
In this article we are going to tell you everything you need to know about the Martian soil, its characteristics and discoveries.
Characteristics of the Martian soil
The properties of Martian soil can vary greatly from those of soil found on Earth. When referring to Martian soil, scientists typically refer to the finer particles of regolith, which is the loose material that covers the solid rock on the planet's surface. Unlike terrestrial soil, Martian soil does not contain organic matter. Instead, Planetary scientists define soil based on its function, distinguishing it from rocks.
Rocks, in this context, are larger materials measuring 10 cm or more, such as exposed fragments, breccias and outcrops, that have high thermal inertia and remain stationary under current wind conditions. These rocks are considered larger grain sizes than cobblestones according to the Wentworth scale. This Functional definition allows consistency between Martian remote sensing methods that use various parts of the electromagnetic spectrum.
Soil, on the other hand, includes all other materials that are generally unconsolidated and can be moved by the wind, even if they are thin. Therefore, Mars soil encompasses a variety of regolith components that have been identified at different landing sites. Several common examples, such as Beds, clasts, concretions, drift, dust, rock fragments and sand are included in this category.
There is a recently suggested definition of soil as found on celestial bodies such as asteroids and satellites. By this definition, soil is an unconsolidated layer of chemically eroded fine-grained mineral or organic material that is more than one centimeter thick. It may or may not contain thicker components and cemented portions.
The fine particles found in Martian dust are typically even smaller than those found in Martian soil, measuring less than 30 microns in diameter (which is 30 times finer than pediatric talcum powder). The lack of a unified understanding of what constitutes soil in the scientific literature leads to disagreements about its importance. While the pragmatic definition of soil as “medium for plant growth” is widely accepted in the planetary science community, a broader definition characterizes soil as “geochemical/physically altered (bio)material on the surface of a planetary body.” which includes telluric deposits. This definition highlights the fact that soil contains valuable information about its environmental past and can form without the presence of life.
Geochemical profile
The surface of Mars is characterized by wide expanses of sand and dust, interspersed with rocks. From time to time, huge dust storms hit the planet, collecting fine particles in the atmosphere and giving the sky a reddish tint. This reddish hue can be attributed to the oxidation of iron minerals, which is probably formed billions of years ago, when Mars had a warmer, wetter climate. However, in today's cold, dry conditions, modern oxidation may be caused by a superoxide that forms on minerals exposed to ultraviolet rays from sunlight.
Due to the extremely low density of the Martian atmosphere, sand is thought to move slowly with winds. In the past, liquid water flowing through ravines and river valleys may have shaped Martian regolith. Current Mars researchers are investigating whether groundwater extraction continues to shape the regolith and whether carbon dioxide hydrates exist on the planet and play a role in its geological processes.
Significant amounts of water and carbon dioxide are believed to remain frozen within the regolith, particularly in the equatorial regions of Mars, as well as on the surface at higher latitudes. The high-energy neutron detector on the Mars Odyssey satellite reveals that the Martian regolith contains water, which makes up up to 5% of its weight. This finding suggests that physical weathering processes currently have a greater impact on Mars due to the presence of an easily weatherable primary mineral, olivineThe accelerated advance of the soil on Mars is believed to be caused by high concentrations of ice in the soil.
Discoveries on the Martian soil
In June 2008, the Phoenix Lander provided data indicating that the Martian soil near the north pole is slightly alkaline and contains essential nutrients such as magnesium, sodium, potassium and chloride, which are crucial for the growth of living organisms. Comparisons made between Martian soil and Earth gardens suggested it might be suitable for plant growth. However, in August 2008, Phoenix Lander conducted chemical experiments mixing Earth water with Martian soil to test its pH.
These experiments confirmed the theories of many scientists, revealing traces of sodium perchlorate and a basic pH measurement of 8,3. The presence of perchlorate, if verified, would make Martian soil even more extraordinary than previously thought. To rule out the possible influence of terrestrial origins, further testing is required to determine the cause of the perchlorate readings, which could potentially have transferred from the spacecraft to the samples or instruments. Although our knowledge of Martian soils is limited, their wide range of characteristics leads us to ask how we can effectively compare them to soils found on Earth.
As you can see, there are many discoveries about the Martian soil and its interest does not stop growing. I hope that with this information you can learn more about the Martian soil, its characteristics and latest discoveries.
