14/09/2025
Life On Mars:
The now-famous Chevaya Falls Rock in Jezero crater, discovered by the Perseverance rover, is the strongest evidence yet of a biosignature of Mars. However, in light of these revelations, historical data need to be studied more closely. Curiosity rover previously detected a seasonal cycle of atmospheric methane. Although no conclusive evidence of a biosignature was found, microbes like methanogens could have initiated such a cycle. Since the 2003 discovery of methane in the atmosphere, scientists have been designing models and in vitro experiments testing the growth of methanogenic bacteria on simulated Martian soil, where all methanogen strains tested produced substantial levels of methane. Research at the University of Arkansas presented in June 2015 suggested that some methanogens could survive in Mars's low pressure. Four species of methanogens survived low-pressure conditions that were similar to a subsurface liquid aquifer on Mars. The Insight Lander, through analysis of seismic data, found large subsurface water bodies on Mars.
Coupled with the experiment mentioned above, it is a definite possibility of subsurface biological activity on Mars. The oldest detection of a possible biosignature might have been the Viking Labelled Release experiment from 1976. The Labelled Release experiment mixed small samples of Martian soil with drops of water containing a nutrient solution and some radioactive carbon. If it detected radioactive carbon, then microorganisms in the soil must have metabolised the nutrients and released the carbon. Air around a control version, in contrast, heated up to temperatures thought to kill microbes, should not have any radioactive carbon. But investigators detected radioactive carbon in the Viking experiment; however, no other organic compounds were detected in the sample. The results of these experiments have been inconclusive and divisive ever since. In light of the recent analysis by Perseverance, all these previous results need to be looked at through a new lens. We might be standing at the precipice of a truly groundbreaking discovery.