The team of researchers in charge of the mission “Mars Science Laboratory” publishes today in the journal Nature an important discovery of Mars . The Martian rover Curiosity has found sedimentary rocks in the vicinity of Gale Crater that suggest the existence of a freshwater lake 3.6 billion years ago . The geological analysis has determined the presence of shales in the ground, a type of sediment characteristic of bodies of water without current, of low salinity and neutral pH, an ideal environment for the appearance of microbial life.
At a sediment outcrop near the planet’s equator, known as Yellowknife Bay, Curiosity drilled 5 centimeters into the subsurface and obtained a dust sample that it compared to surface dust . The results showed that the second had been exposed to ultraviolet radiation, cosmic rays and perchlorates, destroying agents of any trace of organic matter. The first, however, being buried would have been exempt from such erosion.
By heating the underground dust sample, it emitted a large amount of carbon dioxide, in addition to reducing the level of oxygen gas from the decomposing perchlorates, which for the experts is unequivocal evidence of the combustion of organic carbon. Based on this discovery, the scientists venture that the lake would have contained carbon, hydrogen, oxygen, nitrogen, and sulfur, compounds essential for the formation of simple microbial life, such as chemolithoutrophs.
It is one of the most important findings of the rover in its second year of studying the geology of the planet, whose main objective is to find evidence of life during the Noeic Era , the period of time that covers from the formation of the planet to the beginning of volcanic activity. The presence of sediments is not conclusive in this regard, but it does open the doors to the search for organic molecules linked to living beings. Curiosity will therefore delve into rock extraction in the vicinity of Gale Crater, which stretches for 150 kilometers.
