August 6, 2016
Japanese researchers have found that some bacteria are able to survive in harsh space conditions without additional protection. If the colony of microorganisms is large enough, then its outer dying layers act as a shield under which life is preserved. This became clear as a result of three years of observation of colonies of deinococcus bacteria on the external module of the ISS. According to scientists, the results of the investigation indirectly confirm the theory of panspermia about the possibility of the spread of life through outer space.
Biologists at Tokyo University of Pharmacy and Life Sciences have shown that large colonies of certain bacteria can survive without any protection in space for several years. This is reported in the journal Frontiers in Microbiology.
As part of the Tanpopo mission to find opportunities for the spread of life between planets, scientists from 2015 to 2018 conducted a number of biological experiments on the International Space Station. In particular, they placed colonies of bacteria Deinococcus (Deinococcus) in the open research module of the ISS Kibo. The task of scientists was to find out whether these microorganisms, resistant to radiation and lack of oxygen, could survive in harsh space conditions without any protection.
According to the theory of panspermia, life can move from one planet to another, including by natural ways, such as using asteroids. As a result, a theory arose that life on Earth did not appear independently, but was brought in from the outside. It is assumed that living microorganisms are able to move between planets under the protection of solid celestial bodies. Japanese researchers went further and found that bacterial colonies are able to survive in space on their own.
During other research by Dr. Yamagishi and his team, it turned out that live deinococci are found even at an altitude of 12 km above the Earth. Experiments on the ISS have proved that these microorganisms in large colonies are resistant to vacuum conditions, temperature changes and solar radiation.
Various examples with deinococci were carried out on the outer panels of the ISS for one to three years. Even after three years in space, large colonies of bacteria have partially survived. It turned out that the dying surface layer of bacteria served as protection for the core of the colony, where life still smolder.
With the help of computer modeling, it was possible to find out that bacterial colonies with a diameter of more than 0.5 mm could live on the ISS panels from 15 to 45 years. And colonies with a diameter of at least 1 mm could survive for eight years already in outer space, the researchers say. They believe their discovery has brought the proof of the panspermia theory one step closer.