Earth’s deep-sea microorganisms can live on Enceladus



    A few years ago, scientists discovered that Enceladus, the satellite of Saturn, has an entire ocean of liquid water. Of course, it is not superficial. Water splashes under a multi-kilometer layer of ice. Astronomers believe that the ocean is evenly distributed over the entire subglacial surface of the planetoid. There is evidence, and a lot of them. The main thing is hydrothermal emissions, which are found repeatedly, and through which Cassini even flew , a space probe arriving at Saturn in 2004.

    Initially it was thought that Enceladus had lenses of liquid water, the pressure in which leads to a break in the ice crust and emissions. But later, scientists agreed that the basic version is still the existence of the ocean. Indirect evidence is a planetoid oscillation. If it were a completely solid body, then its movement in orbit, or rather, the oscillations during movement, would not be as significant as they are now. The only thing that can influence the change of movement of the planetoid is a huge amount of liquid water under the ice. And it is clear that scientists are now pondering over whether life can exist in this water column. The answer is more likely than not.

    Why? The fact is that there are microorganisms on Earth that can live on Enceladus, under extreme conditions. The fact is that the ocean planetoid most likely contains a huge concentration of salts. And not all living things, even microorganisms, can exist in such conditions.

    Plus, in the water of the planetoid, most likely, there is little oxygen, but a lot of methane, carbon dioxide and hydrogen. All these elements and compounds can serve as an energy source for bacteria. Such bacteria are on Earth, and they feel well in such conditions. Namely - in conditions of enormous pressure, not the most comfortable temperature conditions and the presence of a high concentration of salts in the water.

    To test the assumption of the possibility of the existence of bacteria in Enceladus’s water, scientists carried outseveral experiments in the lab. Bacteria placed in the conditions described above, and it was found that they are ways not only to exist, but to thrive. “Probably, it is precisely such microorganisms that could live on other objects of the solar system,” said Simon Rittman, a microbiologist at the University of Vienna, head of research. "The future missions of mankind should clarify the possibility of the existence of life there."


    The bacteria in question are methanogenic archaea . Some species of such bacteria exist on Earth in deep faults of the Earth’s crust, in the ocean, at high temperatures, which are characteristic of hydrothermal sources. Archaea gain energy by reducing carbon dioxide with molecular hydrogen. In this case, CO2, being the terminal acceptor of hydrogen, is reduced to methane (hence the name of the group).


    Hydrothermal source - it is in such conditions that the bacteria referred to in article

    Best suited for the conditions of Enceladus Methanothermococcus okinawensis, which exist in the most difficult conditions here on Earth. Since Saturn’s satellite contains a lot of hydrogen and carbon dioxide, these bacteria can thrive there. Of course, this is only an assumption, but it is no longer unsubstantiated - a test of the capabilities of these bacteria was carried out in the laboratory. Another assumption is that methane, which is found on Enceladus, may be the product of the vital activity of microorganisms. If there are many of them in the depth of the ocean, then this is quite likely.

    Only an expedition to a planetoid can finally clarify the situation with Enceladus. True, in order for her to get the data, she needs to come back. Or research should be carried out by some kind of apparatus capable of transmitting data to Earth, which is very difficult to organize. Of course, there are already projects to create robotic submarines capable of searching for traces of life, analyzing the information received and transmitting it to Earth. But these projects are expensive and complex.

    Actually, a cheap expedition to Enceladus can not be, and simple, too. So far, only NASA is able to send such an expedition, which, however, is now concentrating on planetary expeditions - for example, flying to the Moon or Mars (the latter option is becoming more and more unreal because of various technical, financial and bureaucratic difficulties).

    But now that people have learned that life can exist on Enceladus, it is possible that resources for such a project will be allocated.

    Also popular now: