History has shown us the dangers of bringing things like microbes, bacteria, and viruses to a new region. When the first colonists arrived in what is now America, they exposed Native Americans to all kinds of awful diseases. Likewise, this is something we need to consider as we start thinking about colonizing space. What sort of organisms can travel in the harsh conditions of space, and which ones might we wrongly identify as native to a new planet? Research taking place on the International Space Station has given us an idea.
We initially believed that no microbial Earth life could sustain the harshness of space and all the way to a planet like Mars. However, the ISS research proves that certain microbes are much tougher than expected, and two, in particular, could easily hitch a ride to another planet. The ISS began its experiments with spore-forming bacteria called Bacillus pumilus SAFR-032, which have previously shown a high resistance to space conditions, as well as spacecraft cleaning techniques involving UV radiation and hydrogen peroxide. The research team created a simulated Mars environment in a test facility on the ISS for their studies. Most of the Baccilus pumilus SAFR-032 spores survived in that environment for nearly 30 minutes. Some, though, managed to survive for a full 18 months in another experiment.
The research team learned more in another test involving these spores, along with another bacteria, Bacillus subtilis 168. Researchers dried the spores on aluminum (simulating a spacecraft’s body) and then subjected them to more than a year in the vacuum of space. These spores were left exposed to both solar radiation and massive temperature changes and then placed in a Mars-like atmosphere. Most of the microbes died, but some — those kept in darkness — survived. This suggests that these spores could easily make a trip to Mars if protected against solar radiation by other spores, or by finding a sheltering nook on a spacecraft’s surface.
Finally, a third experiment tested theories about how such organisms could survive traveling on a meteor to land on another planet: a process called lithopanspermia, that usually takes at least thousands of years. The research team chose organisms that adapt well in harsh conditions on Earth and put them in the testing facility. Some proved able to survive space, but (obviously) the experiment didn’t run the long length of time needed to prove lithopanspermia. It does suggest that it is at least possible in theory, and could even be how life first got to Earth or traveled from Earth to other parts of the solar system.