Last week, Russia’s state news agency, TASS, announced a Russian cosmonaut had told them living bacteria have been found on the outside of the International Space Station.
The lead of Russia’s ISS crew, launching in December, Anton Shkaplerov, had said the station’s Russian segment was swabbed by previous cosmonauts during spacewalks, called Extravehicular Activities, taking samples with cotton swabs from the ISS external surface. They sent their samples back to Earth for analysis, where tests concluded the swabs held bacteria that had not been on the module when it was launched into orbit. The questions immediately arose: Is the bacteria alien? Do they pose a threat to Earth? Or are they stowaways who hitched a ride to the stars?
This report has not been verified, and important information still is missing; including if the report has been vetted by a peer-reviewed journal, or exactly when and how the full experiments on the swabs were conducted.
At this point in time, it is believed a more plausible explanation than the bacteria being of alien sources, is the ISS was contaminated by earthly organisms, which are known for surviving the extremes found in space. It is common knowledge contaminants have been deliberately sent to space, such as E. coli and rocks covered in bacteria, to evaluate how they would react to the conditions found there.
Microbes that have found their way off planet Earth have had to deal with powerful temperatures, cosmic radiation, and ultraviolet light. Earth, however, already has been home to many hardy organisms that can survive in these extreme environments, like the virtually indestructible Tardigrade.
The possibility of finding bacterial contamination from space to Earth, or Earth to space will never be dismissed, because these types of discoveries are precisely what scientists are trying to limit, or contain, if verified. By mutual cooperation and communication, safety for Earth and other planets during exploration will continue to be a top priority, and maintained for the well-being and benefit of all.