When searching for new potentially inhabited planetary bodies, astronomers always pay attention to one aspect – the presence or absence of water on this planetary body. They are so used to it. On Earth there is water, and it is an important and integral part of the maintenance of life on our planet. Therefore, whether it is the bottom of the ocean of Europe (we are talking about the satellite of Jupiter and not about part of the world) or the liquid methane lakes of Titan – we always pay attention to the presence, even not of water, but of some kind of liquid. But is this really important in reality? A new study conducted by the University of Washington, USA, suggests that life can exist even with the minimum amount of liquid available, which means it can also exist on such planets as dry Mars.
The results of this study were published by Proceedings of the National Academy of Sciences. In them, as an example, the most arid region of the most arid desert on our planet – the South American Atacama Desert – is shown. Here for decades there are no rains. The peculiarity of the Peruvian currents cools the lower layers of the atmosphere and creates a temperature inversion that prevents precipitation. At best, their annual rate does not exceed 50 mm. In other words, we have an ideal analog of the surface of Mars.
How can life exist in such conditions?
Scientists know that even in such extremely dry conditions microbial life occurs, but previously the researchers were not sure of one thing: is it Their habitat is native to these microbes, or they migrated here due to weather factors. In the new study, scientists concluded that there is indeed a constant presence of microbial life in this desert.
When visiting Atacama in 2015, after one of the extremely rare rains, scientists witnessed a real flowering of microbial life in local soil. When the researchers returned here two years later, in the collected soil samples they found the same microbial communities. True, the latter began to dry out and fall into a kind of hibernation in anticipation of a new rain.
"It's always interesting to go to places where people think nothing is able to survive, and eventually find that life is somehow has found a way to do it, "says scholar Dirk Schulze-Makuch of the University of Washington.
Schulze-Makuch led this research and made it part of his work on studying the most persistent extremophiles (organisms able to survive in the harshest environmental conditions ) to the Earth . Their study can help to understand how life could spread in the universe.
"If we drop references to the film" Jurassic Park ", our research indicates that if living organisms can survive in the most arid regions of our planet, then , it is possible that life could appear and maintain its presence on the same Mars, "the scientist added.
Of course, the results of the study do not allow us to conclude that the Martian life leads a very secret existence. Nevertheless, they indicate the existence of such an opportunity. This is explained by the scientists' confidence in the fact that in the past there was liquid water on the Red Planet. Martian microbes could develop at this time, and when Mars began to dry out, they could adapt to changing conditions, go deeper into the surface and eventually, as well as terrestrial microbes, fall into a hibernation. Since Mars is a planet much colder than Earth, it contains many ice caps. Scientists suspect that if these caps can somehow be melt, then microbial communities can again "come to life."
The next step for the Washington team of scientists will be the study of extremely cold areas, as well as places with a high salt content, which, in in turn, will allow new parallels to be laid with the Martian conditions.
"There are only a few places left on Earth where one can go in search of new forms of life that managed to survive in environments that are not inferior to Martian ones in severity. Our task is to understand how these organisms survive in such conditions. Thanks to this information we will be able to understand where it is really worth looking for life on Mars, "concluded Schulze-Makuch.