Abstract EANA2024-96

The Viking mission (NASA, 1976) was the only study on planet Mars, in which metabolic life-detection experiments were performed. These experiments were the Labeled Release, the Pyrolytic Release, and the Gas Exchange or the Carbon Assimilation. Those experiments provided contradictory results and were found inconclusive. The present poster reviews data on the temperature under which experiments were performed and discusses possible impact of temperature on their results. During all Viking life-detection experiments temperature was higher than that outside both Viking landers. In some experiments it was a result of heat sources inside landers, whereas in others, it was necessary to maintain the liquidity of the nutrient solution. Each time, the temperature was increased beyond the ambient environmental temperature range and thus might exerted an inhibitory effect on plausible microbial metabolism. However, it should be mentioned that (i) in some regions of Mars temperature seasonally exceeds zero degrees centigrade and is similar to that of the Viking experiments and (ii) Martian regolith with plausible microorganisms, that is, the material used in experiments, is dispersed globally. Therefore, plausible microorganisms could be accustomed to temperature applied during experiments. The poster proposes further metabolic experiments to be performed on Mars.