Fifty Years after Viking: The Promise of Solar System Microbiology and Microbial Ecology

The ambiguity of the Viking lander life-detection experiments left microbiology and microbial ecology out of space missions for 50 years. However, this was largely because the scientific process inherent in the search for life was misunderstood by a space exploration community that wanted clear-cut answers. Since Viking, enormous advances have been made in our knowledge of microorganisms, their biochemistry, and physical and chemical limits. Coupled with improvements in methods for culturing microorganisms and measuring their active metabolism, this has made possible more sophisticated experiments to search for life in extreme environments on Earth and on other planetary bodies. By overcoming misunderstandings surrounding the Viking lander experiments, microbiology and microbial ecology can take center stage in renewed efforts to seek life elsewhere. Furthermore, new knowledge in these fields should be used to overhaul assumptions in planetary protection, and it can be used to achieve permanent human space settlement.