Outer space, with extreme low pressures and frigid temperatures, is the most hostile environment for life. Any life form left in the void of space will soon die. Radiation quickly degrades cell membranes and destroys DNA. However, new research shows that some bacteria can withstand the harsh environment and space.
Deinococcus bacteria are radiation-resistant microbes that thrive in some extreme places on Earth, such as the stratosphere. Balls of Deinococcus bacteria as thin as five sheets of paper were stuffed into small wells in metal plates. These metal plates were placed outside the International Space Station by NASA astronaut Scott Kelly.
Every year samples were sent back to the Earth for analysis. The researchers found that the microbes in the inner layer survived. The outer layer of dead microbes had protected them from the extremes conditions of space. The finding is published in Frontiers in Microbiology.
Akihiko Yamagishi, an astrobiologist at the Institute of Space and Astronautical Science in Tokyo, Japan, was part of a team that sent dried pellets of Deinococcus bacteria to space in 2015.
According to Yamagishi, back home, the returned pellets were moistened, fed, and analyzed. In the 100 micrometer thick pellets, none of the bacteria survived. However, in the 1000 micrometer thick pellets, the bacteria in the inner layer had survived. The outer layer bacteria were discolored by ultraviolet radiation, desiccated, and had died. These dead microbes acted as a protective layer for the bacteria in the inner layer, shielding them from harmful radiations. About 4 out of every 100 survived.
According to Margaret Cramm, a microbiologist at the University of Calgary in Canada who was not part of the study, It is known that microbes could survive inside artificial meteorites. But this is the first evidence that microbes can survive this long unprotected in space. The new finding adds weight to the worry that human space travel could accidentally introduce life to other planets.
Yamagishi estimates that 1,000-micrometer pellets could survive eight years floating through space. This is enough to reach Mars from Earth; some meteors can travel this distance within a few months or years.
Microbial groups like these might be able to drift among planets and spread life through the universe, a concept known as panspermia.
It is not clear how these microbes could get expelled into space. Yamagishi thinks microbes can be kicked into space by multiple means – small meteorites, thunderstorm-induced perturbations to Earth’s magnetic field.
Do you want to publish on Apple News, Google News, and more? Join our writing community, improve your writing skills, and be read by hundreds of thousands around the world!