Back in 1975, the Space Agency sent two probes, Viking 1 and 2, to the Red Planet to study its composition and geographical features. The two probes also collected soil samples and conducted tests to see if there are any signs of microbial life on Mars. The results were not conclusive, so the team abandoned the project.
The experiments conducted more than forty years ago showed contradictory results. One showed no traces of organic material, while the other found traces of a metabolic process. However, the inconclusive tests did not spark enough interest in the scientific community, the experiment being abandoned.
The research was not continued because scientists believed that the positive result was a false positive. The main reason for the controversy was the test, which was conducted on false premises.
The idea of the Viking experiment was that if a sample of Martian soil is exposed to water filled with nutrients and the molecules start metabolizing, then microbial life on Mars would be confirmed. However, after the result came back positive, some researchers argued that the metabolization process could also be accomplished through nonbiological processes.
Now, after numerous probes and rovers were sent to the Red Planet, some researchers believe that the Viking tests should be revisited. Patricia Ann Straat and Gilbert Levin think that NASA has been sitting on evidence confirming microbial life on Mars ever since the 1970’s.
The two scientists argue that recent discoveries point towards the positive outcome of the Viking test as being concludent. Straat and Levin insist that microbial life could be responsible for the organic molecules that were found in Mars’ atmosphere.
Back in 1975, the researchers in charge of the Viking experiments had no idea that the Red Planet was harboring methane, water, and oxygen. This meant that they preferred to apply the principle of Occam’s razor, which dictates that the simplest explanation is usually correct.
The simplest explanation for the contradictory results back in the days was that either something went wrong during the experiment, or that non-biological forces messed with the results, thus creating a false positive.
The two scientists are insisting on revisiting the tests because the discovery of microbial life on Mars could change the outcome of the Mars missions. The crew that will land on the Red Planet needs to be prepared for any foreign pathogens they might meet.
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