Radiation could nourish the life in the crust of ancient Mars and make global warming

SL, Вторник 25 Сентябрь 2018 - 18:24:27

The decay of radioactive elements could provide a hypothetical microbes in the Martian crust energy for hundreds of millions of years. We are talking about that the radiation splits the water into oxygen and hydrogen, and the latter can serve as food for microorganisms. In addition, the emissions of this gas in the atmosphere during geological disasters could cause large-scale warming of the climate of the red planet.

This was concluded in a scientific paper published in the journal Earth and Planetary Science Letters is a group headed by Jesse Tarasom (Jesse Tarnas) from brown University in the United States.

Most planetary scientists agree that in the old days on the red planet splashing oceans and beat hot springs. However, the duration of these wet periods in question. According to modern models, they can only be a moment in the geological history of Mars. Most of the time the temperature there did not rise above the freezing point of water. Therefore, the thickness of the crust of the planet could be more welcoming habitat than its frozen surface.

It will be recalled that at least half of the terrestrial biomass constitute the germs of the earth's crust. They need no oxygen, no sunlight and get energy through chemical reactions.

Many of these organisms spetsializiruyutsya on the hydrogen consumption. The source of this gas is the decomposition of water molecules under the action of natural radiation. Radiation is caused by the disintegration of the contained in the earth's crust radioactive elements, primarily uranium.

Could the same process to be typical of ancient Mars? This issue was discovered by a team of Tarnas.

The researchers used the data receiver of gamma radiation mounted on the orbiting Mars Odyssey. This allowed them to see the number of radioactive isotopes of potassium and thorium in the crust of the red planet. Based on this information, they calculated, and the content of uranium. Given that these elements break up with constant and well known speed, it was easy to calculate their concentration in any geological period. Thanks to this, astronomers have estimated the flux of radiation that breaks down molecules of water.

The next step was to figure out how much moisture could be in the crust of Mars. Roughly estimating its density, scientists have calculated how porous it is and how much water could enter in these pores.

Finally, the question arose, at what depth could dwell bacteria. This area should not lie too close to any cold surfaces or to hot core. The authors found the required depth, based on the model of the internal structure of Mars.

When the researchers summarized the results, they did planetary the layer thickness of a few kilometers. In the period of 3.7–4.1 billion years ago there was enough hydrogen to power of microbes, and these conditions persisted for hundreds of millions of years.

"In calculations based on fundamental physics and chemistry, we have shown that ancient Martian sub-surface layer was probably sufficient dissolved hydrogen to power the global subsurface biosphere, concludes Tarnas. This residential area was similar in conditions to the places on Earth where there is an underground life."

This conclusion is compatible with both "warm" and "cold" models of the climate of the red planet. Last fit even better because the ice sheet does not allow the hydrogen to dissipate.

"People have the notion that cold early climate of Mars was harmful to life. But our conclusion is that in cold climates there were more chemical energy for life underground, says Tarnas. We think it can change people's perception of the relationship between climate and the (hypothetical – approx. edition) ancient life on Mars".

If there were favorable conditions for life, perhaps it is a glimmer still there, or at least left behind fossils? This question need to be clarified in future Martian expeditions.

Interestingly, you do not even have to drill to great depths. Pieces of rock are sometimes struggling to the surface by meteorite impact. Among sites that claim to the title of the landing for the Mars 2020 mission, at least two have similar geological formations.

They came to another curious conclusion. The fall of a large asteroid or massive volcanic eruption could release accumulated in the crust of the planet is hydrogen. Such an event would have caused a short (in geological scale) climate warming, so the average temperature on Mars would rise above zero Celsius.

Recall that "Conduct.Science" (nauka.vesti.ru) wrote about ice lake on the red planet, and finding there the organic and the "gases of life".

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