In 2018, Japanese scientists studied the lower layers stratosphere and bacteria were found at 12 kilometersgenus Deinococcus (Deinococcus). The find surprised scientists because there is a lot of ultraviolet radiation from the Sun above the clouds. The bacteria were not protected from him at all, but, nevertheless, they felt great. Subsequently, the researchers wondered whether these bacteria could survive in open space and move between planets? After all, if this is really so, life on Earth could appear after a celestial object with bacteria from other planets fell on it. To find out if bacteria can survive in the harsh conditions of outer space, scientists conducted a lengthy experiment. The bacteria they collected had to live in outer space for three years. They were able to survive, but not all - some bacteria sacrificed their lives for the benefit of others.
Stratosphere - This is the layer of the Earth's atmosphere, which is located at an altitude of 11 to 50 kilometers.
How bacteria managed to survive inconditions of deep space, it was told in the scientific journal Frontiers in Microbiology. After finding bacteria in the lower stratosphere, the researchers collected the bacteria of the genus Deinococcus and placed them on the outer surface of the Japanese module of the International Space Station. The bacteria were kept in outer space for three years. After the due date, the researchers found that the cosmic radiation only harmed the bacteria that formed the top layer of the group. They turned out to be a kind of "human shield" for microbes that were lucky to stay in the inner layer.
How long do bacteria live?
Based on the results of the experiment,scientists were able to calculate the approximate lifespan of bacteria collected in groups of different sizes. So, microbes of the genus Deinococcus, collected in a group 0.5 mm thick, can live in open space from 15 to 45 years. But large groups of bacteria 1 millimeter thick or more are able to withstand life in open space for no more than 8 years. Why small groups are more tenacious than large, scientists have not explained. Probably, the reason for this difference lies in the area occupied by microbes and the distance between them.
The likelihood of extraterrestrial life
According to study author Akihiko Yamagishi(Akihiko Yamagishi), many people tend to believe that life in the universe is extremely rare. Some are absolutely sure that there are no living organisms anywhere except on our planet. However, if bacteria are indeed capable of surviving in outer space, then the likelihood of the existence of life somewhere other than Earth increases many times. After receiving the results of the study, Akihiko and his team put forward the assumption that life on our planet originated thanks to microbes that flew from Mars. The journey from the Red Planet to Earth would just take several months, which is quite enough for the bacteria to survive.
See also: Life on Earth - a common occurrence in the Universe?
In general, the hypothesis about the extraterrestrial origin of life is called panspermia... A kind of "spacecraft" forbacteria from other planets could easily become meteorites and asteroids. But a lot of them fell on our planet and such cases are still not rare. Considering that space objects fall on other planets, then life may well exist outside the Earth. In general, aliens may not turn out to be a fairy tale, but a completely scientifically based truth. Only one thing is puzzling - during the passage through the atmosphere of the planets, all objects are exposed to very high temperatures and burn up. Then why didn't the bacteria that initiated life on our planet burn out? Perhaps the answer is that millions of years ago, the Earth was arranged completely differently than it is now.
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How life could arise onTo the Earth, in the first half of 2020, my colleague Lyubov Sokovikova also wrote. After the formation of our planet, it took nature another 400 million years to create the first animals, she said. After reading her material, the realization came to me that humanity has still existed for a negligible time. In general, I recommend to start reading this article right now!