The 3.7 million-year-old Martian soil has led researchers to speculate that life may still exist on the Red Planet. Images taken by the Curiosity rover in Gale Crater show soil profiles with cracked surfaces. Similar soils exist on Earth - the Dry Valleys in Antarctica and the Chilean Atacama Desert.
Chemical analysis has shown that Martian soil is structurally similar to Earth's soil, which contains microbes. Geologist Gregory Retallack of the University of Oregon believes that his research confirms the real possibility of the existence of life on Mars, not only in the past, but also now.
This discovery was made on the basis of images and data from the camera of the Curiosity rover. This is further evidence that microbes could live on ancient Mars. The research results were published in the scientific journal Geology. A summary of the article appears in the Daily Mail.
Retallak independently studied the mineral and chemical data published by researchers with wide access to the Curiosity mission.
The researcher points to the processes that often occur on Earth - chemical weathering and accumulation of clay in soils due to the mineral olivine. But most of all he was interested in the depletion of phosphorus in soils, since on Earth it is associated with the activity of microorganisms.
Ancient soils are not direct evidence of life on Mars, he said, but they point to a warmer and more important climate on this planet in the past that is more livable. For the past three billion years, Mars has had a completely different climate.
Chile's Atacama Desert
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Curiosity is currently investigating the upper and younger layers of the crater soil, which Retallack believes are less habitable. The scientist believes that it is necessary to study more ancient and clayey areas, but this will require new missions.
Features such as the porous structure of Martian soil and sulfate concentrations - typical of desert soils on Earth - are inherent in ancient layers of Martian soil and uncharacteristic for its younger layers.
According to Malcolm Walter of the Australian Center for Astrobiology, who was not involved in the study, the discovery of fossilized soil in Gale Crater dramatically increases the chances that Mars is still supporting microbial life.
In his work, Retallack also cites Stephen Banner, a professor at the Westheimer Institute of Science and Technology in Florida, who believes that life originally originated on the Red Planet, not on the water-rich Earth.
