A recent claim by scientist Dirk Schulze-Makuch suggests that NASA’s Viking landers, which touched down on Mars in 1976, may have inadvertently encountered and potentially killed Martian life hidden within rocks on the Red Planet. Schulze-Makuch, an astrobiologist at Technical University Berlin, proposes that these resilient microorganisms may have been overwhelmed by the experiments conducted by the landers, leading to their demise. He argues that similar extreme life-forms exist on Earth, making the possibility of Martian counterparts plausible.
The Viking landers executed four experiments on Mars, with some producing puzzling and conflicting results. The labeled release and pyrolytic release experiments hinted at metabolic activity, while the gas chromatograph mass spectrometer (GCMS) detected traces of organic compounds, initially considered Earthly contamination. However, the gas exchange experiment yielded a negative result, leading most scientists to dismiss the notion of Martian life.
Schulze-Makuch suggests that excessive water used in the experiments may have skewed the results. Mars, while predominantly arid, does have some humidity, and certain microbes can thrive in dry conditions by residing within hygroscopic rocks. These rocks can draw in minimal moisture from the surrounding air. Adding water, however, could have been detrimental, as demonstrated by studies on Earth where excessive flooding killed indigenous microbes unable to adapt to wetter conditions.
In contrast, some scientists argue that the Viking results are less ambiguous than Schulze-Makuch suggests. They point to the presence of perchlorate and its byproducts on Mars, which can explain the gases detected in the Viking experiments. This consensus dismisses the need to invoke the existence of a unique Martian life form. While the debate continues, it raises intriguing questions about the potential discovery and accidental elimination of Martian life nearly five decades ago.