What will happen to the microbes that make their way onto the ship "hare"
Understanding the limits of what microbes can survive is essential to prevent future pollution on Mars when Earth humans and robots arrive. This is also necessary to eliminate possible errors in identifying organisms that we can bring with us in our search for alien life. That is why scientists want to find out if terrestrial microbes can in principle survive on Mars.
In October 2015, a huge exploration balloon with samples reached an altitude of 31 km above Earth to determine the possible fate of bacterial "random fellow travelers" capable of infiltrating spaceships flying to Mars. The experiment showed that in direct sunlight, most bacteria died from ultraviolet radiation, which means that they will die quickly on the surface of Mars.
The E-MIST experiment (Study of microorganisms in the stratosphere) became a new stage of research. This time, the scientists took an extremely resistant microbe in its protective form, the endospore, which some bacteria form under adverse conditions. The researchers lifted them into the stratosphere, which in many respects corresponds to the conditions on the surface of Mars.
When the samples returned to Earth, it turned out that after nine hours at altitude, 99.999% of the bacteria died. Some survived and showed a few small changes in DNA compared to the control bacteria. The result suggests that if some microbes that "hares" entered the ship and survive the flight to Mars, they will undergo genetic changes. However, further research is needed to determine whether the mutations found actually affect microorganisms and contribute to their survival.