Clay is, there is no life - new Curiosity results

    Curiosity has come to its senses for the second week after a radiation impact, but the main thing he managed to do is to send the results of the study of soil from the well. There were fears that it was during their shipment that he “hung”, but nothing happened. Data received, analyzed and made public.

    The main news is clay! The very clay that Opportunity went to for three years, I searched for half a year, but when I found it, I could not really study it. Curiosity found and studied it on 200 sols of his Martian career, just by drilling the first, test well. I thought the intrigue will continue for another year, because the nearest clay deposits from the satellite were discovered 3 km closer to the mountain, but even NASA did not expect such a gift / trick. But the catch is serious - there is no life, although there is organic matter.

    The main message of the press conference:"Curiosity has found evidence of favorable living conditions in the past."
    These conditions are characterized by a humid environment in which there were compounds of sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon. But more importantly, this medium was pH neutral. Such favorable conditions are characteristic of one of the most ancient geological periods of Mars - Noysky. It is named after the land of Noah - the area most intensely pitted with craters, i.e. the oldest. At that time there was pure liquid water, there was a dense atmosphere, there was a magnetic field, i.e. formally, the planet did not differ in conditions from the Earth. This is the basis of all hopes to find traces of microbial life on Mars.

    Water eroded volcanic rocks and they formed clay deposits - smectites or phyllosilicates (these are synonyms). The CheMin X-ray diffractometer shows that the volcanic sand from the Rocknest site is in many ways similar to the clay from the John Klein site - this is explained by the fact that they have almost the same mineral base - olivine-pyroxene volcanic rocks. The difference is that John Klein worked with pH-neutral water and, as a result, 20% of the phyllosilicates shown in the picture.

    Then the era changed, the heaviest asteroids fell to Mars , the core stopped forever, the magnetic field disappeared, and the awakened volcanoes filled the atmosphere with sulfur and chlorine compounds, making the water on the surface acidic and unsuitable for life.

    Geological layers formed with acidic water were studied by Opportunity on the Meridiani Plateau immediately after planting.

    (The color of the images is balanced under terrestrial lighting conditions. )

    Their characteristic feature is the brown color from iron oxides. Therefore, when scientists saw the light gray soil mined by Curiosity in the place of John Klein, they were surprised, but then did not even assume that they would be in control of the new Holy Grail of Mars - the long-awaited clay. Previously, they looked with the same zeal for evidence of surface water activity - they were found by Opportunity. Then they searched for water ice - it was found by Phoenix Lander and the satellites MRO and Mars Odyssey. NASA has tried so hard that so far some are convinced that Americans continue to search for water.

    Meanwhile, NASA is no longer surprising the water on Mars. The same SAM device isolated it from the collected clay:

    More interestingly, this water is lighter than that which was examined in the soil of the Rocknest site . Let me remind you, in studies conducted 4 months ago, the water found in the sand was five times “heavier” than the water on Earth. " Heavy"they call water, in which heavy isotopes of hydrogen — deuterium — prevail in the composition of the molecules. In the Earth’s oceans, one atom of deuterium accounts for 6400 atoms of the light hydrogen isotope — protium. Accordingly, water with a ratio of 1 atom of deuterium to 1280 atoms of light hydrogen was found in Martian soil. But in the Martian clay John Klein singled out the water that was easier than Rocknest. It is true how much easier it is not specified, but the very fact points to open a new method of dating geological layers.

    The difference in the "ease" of water causes by the fact that at least the existence of water on the surface of Mars, under the influence of solar radiation and radiolysis, the atoms of light hydrogen were released and left the atmosphere of the planet. Accordingly, protium flew away, but deuterium remained, its concentration increased. But water, which turned out to be bound at the molecular level in the geological rock, avoided such degradation, so now the D / H ratio in minerals will allow for relative dating. Perhaps if scientists can build a chronological scale of the process of hydrogen degradation, a means of absolute dating of the rock will appear, but this is still in the future.

    In the meantime, we can say with a considerable degree of certainty that Curiosity has drilled into the bottom of the lake, which is about 3.5 billion years old.

    The high thermal inertia of the rocks (red on the map) indicates the boundaries of this lake, due to the fact that bottom rocks differ from the others in the high percentage of water content. Water has a high heat capacity, therefore this soil characteristic was detected from the Mars Odyssey satellite. When Curiosity set out to explore this place, no one knew what he would find there.

    So, there is pure liquid water, there is a nutrient medium ... And there is organic matter!

    But too simple to be proof of a past life on Mars. Signs of chloromethanes were discovered back in Rocknest, but then NASA said it did not vouch for the Martian origin of this organics. Now there is no doubt - local hydrocarbon. But its origin is quite possible without the participation of wildlife. Just look at Wikipedia: Dichloromethane - Obtained by direct chlorination of methane with chlorine under a radical mechanism at 400-500 ° C ... The result is a mixture of all possible chlorides: chloromethane, dichloromethane, chloroform and carbon tetrachloride. Apparently, the necessary conditions and ingredients, except methane, could provide volcanoes. And with methane, not everything is so simple. Although its clusters on Earth are associated with the activities of the biosphere, a similar mechanism is excluded for the atmospheres of Jupiter or Titan, where there is much more methane than on Earth. Where does methane come from on Mars is still an open question, but only big optimists can associate its origin with the biosphere.

    However, NASA does not give up. It intends to carefully study the process of diagenesis - that is, the formation of solid sedimentary rocks from loose sediments. The main question: what conditions and processes did the studied deposits survive, and could any complex organic compounds be preserved in such processes? That is, now the pursuit of Martian life passes from the hands of the drivers of Mars rovers to the hands of experimental chemists. Will they be able to simulate conditions in which all Martian life decomposes to chloromethanes and inorganic compounds, or can the dream of Martians be forever buried? Although, let's not forget that this is only the very first test at the very beginning of a long journey.

    Sharpe Mountain is waiting ...

    Other panorama sizes: VK. or View on GigaPan.

    Those who faithfully hold hope for Martian life still have consolation. Curiosity drilled only 7 centimeters. And although, even at such a depth, clay has not changed its properties in 3.5 billion years, we cannot look deeper yet. On the way of the rover, there will also be meteorite craters, there will be a channel similar to a river at the foot of the mountain, filled with the same ancient clay, there will be a mountain canyon but ... 7 centimeters.

    In 2016, an InSight mission with a drilling platform is planned , which will deepen by 6 meters and will study the tectonic structure of Mars. But the search for life is not yet included in her plans.

    In 2018, they promise a rover from the ESA and Roscosmos - ExoMars .

    Its main tool is a 2.5 meter drill. And he will fly to seek life regardless of the results of research in Gale Crater.

    In 2020, NASA promises another Curiosity, but what tools and devices will be in its arsenal and what goals it will pursue on Mars is not yet known.

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