Life on Venus could theoretically be brought from Earth. This was announced by Russian scientists at the International Meeting on Cloud Habitability of the Second Planet of the Solar System.
Is there life in the clouds of Venus? The world’s leading astrobiologists will try to answer this question within five days. The International Meeting on Venus Cloud Habitability began on November 29 online. One of the organizers of the meeting was the Space Research Institute of the Russian Academy of Sciences. “MK” got acquainted with the main topics of the reports.
So, on Monday, November 29, researchers gathered to discuss the formation and stability of Venus’s clouds, their potential as a home for Venusian life forms.
Many reports were devoted to reasoning and evidence about the possible habitability of the second planet of the solar system.
American, Russian and European scientists noted that Venus and Earth have a lot in common: they are similar in size, mass, gravity, both have an iron core surrounded by a mantle, and a thin crust. But the dense atmosphere, lack of water and high surface temperatures, of course, distinguish Venus from our planet. And on it there is a monstrous pressure at the surface – 93 times higher than the Earth’s, an atmosphere consisting of almost one carbon dioxide, excluding nitrogen impurities, and a cloud of sulfuric acid.
Employees of the Rajarat University of Sri Lanka said that the planet’s atmosphere is constantly covered with layers of toxic clouds: a layer of haze, a lower cloud layer, a middle cloud layer, an upper cloud layer and an upper haze. Scientists report that unnatural dark streaks have been found at the top of the Venusian clouds. And these dark streaks exhibit a strange habit of absorbing ultraviolet radiation. They offered two options for explaining this phenomenon. First, it can be ice crystals or some inorganic compounds such as ferric chloride. Secondly, small particles are nothing more than microbes that once moved to clouds from the surface a long time ago.
What allows scientists to assume that there is life on Venus? They believe that a billion years ago, Venus may have been covered in oceans, the contents of which have evaporated over time. But if there was a lot of water, some life forms could migrate to the clouds. The lower cloud layer of the Venusian atmosphere (between 62 and 73 km from the surface) with a temperature of about 60 degrees Celsius is one of the main goals of studying life because of its favorable conditions for the life of microorganisms, the researchers say. There must also be water molecules, carbon and other necessary elements. “Because of the anaerobic atmosphere, this life would probably be anaerobic,” astrobiologists suggest.
What microorganisms could theoretically survive in such conditions? Several groups of scientists cite well-known terrestrial bacteria as an example. Thus, Russian scientists from Ugra State University (Khanty-Mansiysk) note that Venusian clouds can be inhabited by polyestremophilic organisms capable of surviving in an acidic environment at extremely low pH values and water activity. These hypothetical microorganisms, according to our scientists, could originally exist on the surface of the planet, which could have been suitable for life in ancient times. However, they do not exclude the “settlement” of Venus with biota from other cosmic bodies, including the Earth.
Polish scientists from the Institute of Materials and Biomedicine have added to the list of terrestrial microorganisms that can be guided by studying the characteristics of probable microorganisms on Venus. For example, they argue that the very low pH environmental conditions in Venus’s lower cloud are suitable for microorganisms that are analogous to terrestrial bacteria of the species Acidithiobacillus ferroooxidans. They can live and develop under anaerobic conditions. Hypothetically, a giant “bioaccumulator” of bacteria called exoelectrogens may also exist in the lower cloud layer of Venus. They can generate electricity! Examples of such electrical bacteria on Earth include Geobacter sulfurereducens and Shewanella oneidensis. True, according to a group of British and American scientists, the possibility for the survival of any kind of organisms resembling terrestrial ones on Venus may be negligible, because due to the proximity to the Sun, the planet is exposed to stronger ionizing radiation than the Earth, and moreover, it has no protective magnetic field.
Naturally, several space agencies are preparing their missions to Venus at once in order to test the above hypotheses. And one of the tasks will be to test the version of the existence of a phosphine biomarker in the clouds of this planet, about which several scientific articles were written at once last year.
So by 2029-2031 Russia plans to launch the Venera-D mission to Venus. In addition to a large program for the study of the atmosphere, and phosphine in particular, our scientists plan to plant their module on the planet. It will live on the surface for only 2-3 hours, “examining” the surface and transmitting the image to the Earth, and after that it will inevitably burn out due to the high temperature on the surface – 462 degrees Celsius.
American scientists from the Goddard Space Flight Center (NASA) talk about their upcoming mission to Venus called DAVINCI +. It is also slated for the end of this decade. Its purpose is to study the chemical composition of the atmosphere of Venus “in order to understand how it formed, evolved and to determine whether there was once an ocean on Venus.” The probe, which will descend to the surface of Venus for 63 minutes, will analyze the chemical composition of the planet’s atmosphere and explore the characteristics of its surface. It will be the first US spacecraft to enter Venus’s atmosphere since 1978, when the only spacecraft to land on the planet’s surface operated for 68 minutes.
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