Microbes on the International Space Station & the Possibility of Alien Life

In the vacuum of space, something is stirring! An organism, unknown to our world, mutates and grows, spreading and thriving as it establishes a home on a vessel in which the occupants are clueless to its existence. This situation is not some sci-fi horror story—it happened on the ISS (International Space Station).

In 2017 Anton Shkaplerov, a Russian astronaut, discovered bacteria while taking samples on a spacewalk. Although the bacteria were of terrestrial origin, it still managed to mutate and thrive, becoming functionally different from its Earth counterparts. Microbial life reaches all corners of the Earth and survives in the very harshest of conditions.

In fact, a wide array of microbial organisms have braved the vacuum of space. Due to the ability of microorganisms to survive in severe environments such as space, scientists believe the most likely forms of alien life that humanity may encounter are microbial.

Scientists of the Mars Analogues for Space Exploration(MASE) project propose that Earth’s most extreme conditions could potentially mirror extraterrestrial environments where microbial life could potentially exist. More specifically, they pointed to the similarities between Earth’s most extreme environments and that of Mars. After examining sulfuric springs, briny mines, acidic lakes, rivers, and permafrosts, scientists found that bacteria are not only present but thrive!

Organisms that survive in such conditions are known as extremophiles, all of them having unique adaptations to survive. Perhaps the most impressive adaptation is the ability to survive whilst being oxygen deprived, a trait that would be useful in an environment similar to Mars or space itself. Mars is believed to be primed for life because under the desert of rusted iron there lies massive sheets of ice, and long ago it was believed that Mars had an environment similar to Earth.

Some forms of microbial life also can survive space itself! If one is familiar with the water bear, otherwise known as the tardigrade, they will know that it is an extremely tough creature. In fact, when 3000 or so water bears tagged along on the ESA’s (European Space Agency) Orbital Foton-M3 mission for 12 days, many of them survived! Water bears aren’t the only organisms hardy enough to brave the vacuum of space. A similar experiment was conducted on spores of Bacillus subtilis; after being exposed to space for six years, 80% made the journey back home. The resilience of microscopic organisms fuels the dream of one day encountering alien life.