Microbial test: Can this planet support humans?
Suppose we find a planet that looks habitable, based on physical factors of temperature, solar spectrum, water, elemental composition and so forth. But how can we really tell? What if we missed something, before we step down and try to live there? SFreader suggests we can try out some terrestrial microbes, and see if they survive and colonize the new world.
Which microbes would you test? And which organisms after that?
My first microbial suggestion: Desulforudis audaxviator grows deep underground, probably off hydrogen gas (H2) generated by radiolysis–chemical reactions from ionization caused by radioactive decay. The bacterium was discovered in a South African gold mine; it is believed to have been isolated underground for millions of years, although that is hard to prove. It needs no organic food, but adds reducing electrons to sulfate, and fixes carbon from carbonates. Because it grows underground, it is protected from cosmic rays; such a bug is a good bet to grow on Mars.