Live bacteria were found outside the International Space Station, a Russian cosmonaut told the state news agency TASS this week.
Anton Shkaplerov who will lead the Russian ISS crew in December, said that previous cosmonauts cleaned the Russian segment of the station during spacewalks and sent the samples to Earth. The samples came from places in the station that had accumulated fuel waste, as well as other dark nooks and crannies. His tests showed that the swabs contained types of bacteria that were not in the module when they were originally launched into orbit, says Shkaplerov.
In his interview with TASS, Shkaplerov says that the bacteria "has come from outer space and settled on the outside" surface ", a claim that caused some media to broadcast frantic reports about the aliens that colonize the space station
For now, however, details about the cleanup experiment are scarce on the ground, and Shkaplerov did not see if the study was examined by a peer-reviewed journal, which means that it is not clear exactly when and how performed the complete experiment, or how the team avoided the contamination of much more mundane bacteria in the cosmonauts or in the Earth lab of destination The requests for interviews with the Russian space agency did not receive a response when this article was published.
More than microbes raining from outer space, it is much more plausible that the outer space station has been contaminated by Terrestrial organisms, many of which can survive in the harsh environment in orbit
Leaving our mark
In the void of space, microbes have to deal with turbulent temperatures, cosmic radiation and ultraviolet light. But Earth is home to many resistant organisms that can survive in extreme environments, such as the virtually indestructible tardigrades. Sometimes, researchers intentionally send terrestrial contaminants, such as E. coli and bacteria-covered rocks, into space to see how they will react.
And TASS reports that in a previous ISS mission, the bacteria accidentally hooked up to the station in tablets and other materials. The scientists sent these objects to see how they would go in space, and the freeride organisms managed to infiltrate the outside of the station. They stayed there for three years, defying the temperatures that fluctuated between -150 and 150 degrees centigrade.
Such discoveries present concerns for scientists trying to limit the spread of human germs in other worlds.
In 1967, the General Assembly of the United Nations adopted the Outer Space Treaty, which establishes the framework for international space law. In addition to other principles, the treaty requires that any mission sent from Earth avoid the harmful contamination of celestial bodies.
NASA in particular has established strict limits to its interplanetary pollution. The Apollo astronauts were quarantined when they returned from their missions, for example, to prevent extraterrestrial germs from going out into the world. And almost all of Earth's equipment is sterilized before it heads toward the sky, either with extreme heat or an alcohol bath, depending on its intended destination.
These treatments are especially important for missions sent to Mars, which once could harbor their own life forms, leaving fossil footprints on rusty rocks.
"If you want to find life on Mars, you must get rid of it" from the signs of terrestrial life so you can see it, "NASA scientist Catharine Conley told National Geographic in September 2016. Conley heads the Office Planetary Protection of the administration, which aims to reduce pollution between the Earth and other planets.
Even so, total sterility is impossible, which is why the guidelines limit the amount of microbial contamination in flight systems to 500,000 bacterial spores, which is about one-tenth the amount of spores in a teaspoon of seawater, specifically, Mars rovers are limited to 300,000 bacterial spores on their surfaces.The hope is that even if some bacteria from the Earth will be thrown to the robots, they would die in the harsh Martian environment.
But all bets may be off when we manage to send humans to explore Mars, writes Emily Lakdawalla of The Planetary Society: "Once we put humans on the surface, living or dead, it becomes much, much more difficult to identify native Martian life."