Since 2012 theCuriosity is conducting investigations on the surface of Mars with the aim of better binding and the presence of water in its past, but also to determine if Mars was ever able to sustain life.
If we know nowthey shaped the Martian landscape and this is his it was a favorable day for life, no direct biological trace has yet been found. Never mind, scientists continue to search, particularly by examining the presence of the elementary chemical building blocks needed for the of life.
A quantity of organic carbon comparable to that of some terrestrial regions
In 2014,then carried out a series of experiments to measure the fraction of total organic matter contained in Martian rocks. After eight years of data analysis, the results are finally available in the journal and reveal that Martian rocks are relatively rich in organic carbon, which is one of the key components for setting chemical reactions in motion. and potentially the of biological molecules.
It has been a while since scientists found traces of organic carbon on the. But the assessment of its available quantity is an important parameter, which determines the development potential of life. And the results are quite surprising, as they show that Martian rocks contain a significant fraction of organic carbon, comparable to some regions on Earth. Admittedly, the values are quite similar to those of hostile environments depleted of organic carbon (for the terrestrial), as , but these are encouraging results for Mars. Because it shows that carbon was available in sufficient quantity for construction (hypothetical) which are the basis of all forms of life known to date.
Water, carbon, sources of energy … all the ingredients of life together
Total organic carbon is defined as the amount of bonded carbon atoms in organic molecules (usually composed of hydrogen atoms,and’ ). If much of the organic carbon on Earth is biological in origin, it may have non-biological origins, in particular , volcanic activity or certain chemical reactions on the planet’s surface. The presence of organic carbon on Mars therefore in no way proves that life ever developed on this planet.
With water in the liquid state, the presence of organic carbon in significant quantities is instead a new element that indicates that the basic ingredients necessary for life were present on Mars a few billion years ago. It would have been the Gale crater in which Curiosity evolvessince in addition to water and carbon, the environment had the other essential elements: the sources of low acidity, oxygen, nitrogen and sulfur.
Curiosity could therefore be in the right place to discover the first traces of Martian life so sought after. However, if they exist, access may be more difficult than we thought.
Review the search strategy for organic molecules such as amino acids
A new experiment conducted by thesuggests that in order to be able to find organic molecules, the rover would have to drill two meters deep into the Martian subsoil. This applies in particular to research which may or may not be of biological origin, but which in all cases are considered constituent elements for the construction of . in any case, the amino acids are fragile and easily destroyed reach the surface of Mars whose thin it does not provide effective protection. Currently, the rovers are drilling to a depth of five centimeters. Scientists estimate that at this depth, amino acids are destroyed in just 20 million years. Knowing that potential Martian life may have developed several billions of years ago, investigating this very superficial level therefore appears completely futile.
These results, published in, show the need to implement a new search strategy for rovers currently in operation, which unfortunately are not equipped to drill to the required depth. A solution would be sought having recently exposed deep parts of the subsoil, such as in small impact craters less than 10 million years old or in material ejected from such craters.