About three weeks ago, Dr. Dirk Schulze-Makuch (Geology Dept., Washington State University) delivered a paper in which he suggests that the Viking probes may have inadvertently destroyed Martian bacteria. He theorizes that if their optima differ significantly from “median” terrestrial bacteria, the tests of the probes – heating, adding water – would be lethal. His speculations, if correct, could explain and reconcile the contradictory results from the biological experiments conducted by the Viking landers.
This shows how our lack of an independent second life sample limits our horizons. In 1976 and 1977, the years of the Viking landings, extremophilic bacteria were unknown. Even after their discovery, it took heroic measures to propagate them once they left their native habitats. Also unknown were the thriving communities of fragile, gelatinous animals living in the ocean depths: the methods used to capture samples shredded them to confetti. Something similar may happen when we look for life under Europa’s ice sheet and in the Mars polar ice cap – the destination of the upcoming Phoenix expedition.
The instruments of the Phoenix lander are still configured to look for life “as we know it”. But this time, the excuse of ignorance will not avail us. Now we are aware that even terrestrial life pushes the boundaries of what was once considered possible. We should put that experience to use. Otherwise we may literally step on alien life and deprive ourselves of unique, irreplaceable knowledge.
Dr. Schulze-Makuch’s theory in detail: