Evidence of Life on Mars?

American Scofflaw

It would be nice to be vindicated after all these years.

A brief recap:

Back on the Viking Mission, we had two experiments looking for life. The first was a simple test of tossing some Martian soil into a radioactively tagged nutrient solution and testing for the release of radioactive gas as a byproduct of metabolism. That test returned a positive result for a while. Then the reaction subsided. The explanations for the fading result included the possibility that the particular nutrients were toxic to the martian microbes over the long run to the suggestion that we had simply over-fed them and literally drowned them in food!

So scientists turned to the second experiment, which was to look for organic molecules in the martian soil using a mass spectrometer. This experiment produced a negative result. On the basis of that negative, NASA management decreed that Viking did not detect life on Mars and that the first experiment yielded a "false positive" on the basis of some poorly understood chemical interaction.

From later probes we now know that the Martian soil contains perchlorates. When heated, perchlorates will combine with and destroy organic molecules. The Viking organic mass spectrometer was doomed to fail by the Martian soil chemistry. No amount of organic molecules could be detected because the process by which the sample was being tested destroyed any organic molecules that might be present.

Therefore, we are left with the one positive result. Viking may indeed have detected life on Mars back in 1976.