We tested whether microbes could survive on the surface of Mars, on a collaboration between the Aerospace Microbiology group at the German Aerospace Center (DLR) and the Aerobiology Lab at NASA Ames research center. The resutls of our MARSBOx mission were published today in Frontiers in Microbiology and you can read more about it here!
On September 2019, we sent a scientific balloon way up to the stratosphere, at ~38 km altitude, and exposed four microbes to simulated Martian environment (atmosphere, pressure, temperature and radiation). We found out that spores from the fungus Aspergillus niger (more commonly known as mold) could temporarily survive under Mars surface-like conditions. We saw they could survive for at least 5 hours under intense UV radiation, and can probably survive longer if they find a way to protect themselves from the harsh radiation.
Seems like fungal spores make very good astronauts! We should definitely think of bringing them along to our future Mars habitat and use them in the production of food and materials.