We have certainty now, the basic components of life were on its surface

Since 2012, it has become rover Curiosity is conducting investigations on the surface of Mars with the aim of better confinement Climate evolution of the red planet And the presence of water liquid in the past, but also to determine whether or not Mars is capable of supporting life.

If we know that now Many lakes and rivers You have formed the landscape on Mars and this is climate It was a fitting day in life, and no direct biological trace has yet been found. Regardless, scientists continue to research, particularly by looking at the presence of the basic chemical bricks necessary forAppearance of from life.

Amount of organic carbon comparable to certain terrestrial areas

in 2014, Curiosity of Thus, a series of experiments were carried out to measure part of the carbon The sum of the organic matter found in the rocks of Mars. After eight years of data analysis, the results are finally available in the journal PNAS It reveals that Martian rocks are relatively rich in organic carbon, which is one of the main ingredients for starting chemical reactions in motion Prebiotics It may be Construction of biological molecules.

It has been some time since scientists found traces of organic carbon on red planet. But the assessment of the amount available is a major factor that determines the potential for life development. The results were somewhat surprising, because they show that the rocks of Mars contain a large portion of organic carbon, comparable to certain terrestrial regions. Admittedly, the values ​​are somewhat similar to those in harsh environments depleted in organic carbon (for Store terrestrial), as Atacama desert, but these are encouraging results for Mars. Because it shows that carbon was available in sufficient quantity for construction (default) organic moleculeswhich is the basis of all life forms known to date.

Water, carbon and energy sources… all the ingredients of life together

Total organic carbon is defined as the amount of carbon atoms attached to organic molecules (usually made up of hydrogen atoms,Oxygen And the’nitrogen). If a large part of the organic carbon on Earth has a biological origin, it can have non-biological origins, in particular meteoritesOr volcanic activity or certain chemical reactions on the planet’s surface. So the presence of organic carbon on Mars in no way proves that life evolved on this planet.

With liquid water, the presence of organic carbon in large quantities on the other hand is a new element that indicates that the basic components necessary for life were already present on Mars a few billion years ago. It could have been Gale Crater where Curiosity developed A suitable place for the emergence of lifebecause in addition to water and carbon, the environment contained other essential elements: sourcesenergyLow acidity, oxygen, nitrogen and sulfur.

Therefore, Curiosity could be in the right place to discover the first traces of required Martian life. However, if it does exist, it may be more difficult to access than we thought.

See the strategy of searching for organic molecules such as amino acids

I did a new experiment NASA It is already suggested that for a chance to find organic molecules, the rover must dig two meters deep into the Martian subsurface. This is especially relevant to the search foramino acidswhich may or may not be of biological origin, but are in all cases the building blocks of construction protein. However, the acids Amino acids are fragile and easily destroyed cosmic rays Reaching the surface of Mars, which is thin atmosphere It does not provide effective protection. Currently, roving vehicles dig to a depth of five centimeters. Scientists estimate that at this depth, amino acids are destroyed in just 20 million years. Knowing that possible Martian life may have evolved several billion years ago, investigating this very surface level seems completely useless.

These results have been published in astrobiology, the need to implement a new search strategy appears for the currently operating roving vehicles, which unfortunately are not equipped to dig to the required depth. One solution is to find it bumps It has recently revealed deep parts of the Earth’s interior, such as in small impact craters less than 10 million years old or in material ejected from these craters.