An extensive microbial life on Mars was discovered long back in 1976. These are the findings of a major study recently conducted by a team of researchers from the Arizona University, Tempe and the National Instituted of Health.
In “The Case for Extant Life on Mars and Its Possible Detection by the Viking Labeled Release Experiment,” coauthors Gilbert V. Levin, Arizona State University, Tempe, and Patricia Ann Straat, National Institutes of Health, Bethesda, MD (retired), clearly outline the evidence to support the “biological hypothesis”, which argues that the results of the 1976 Viking Labeled Release experiment were positive for extant microbial life on the surface of Mars.
Further, Drs. Levin and Straat evaluate the “non-biological hypotheses” to explain the Viking results, which many scientists support, but the authors conclude that the experimental evidence supports a biological explanation and the likelihood that microorganisms were able to evolve and adapt to be able to survive in the harsh conditions of the Martian environment.
“Even if one is not convinced that the Viking LR results give strong evidence for life on Mars, this paper clearly shows that the possibility must be considered,” says Chris McKay, PhD, Senior Editor of Astrobiology and an astrobiologist with NASA Ames Research Center, Moffett Field, CA. “We cannot rule out the biological explanation. This has implications for plans for sample return from Mars and for future human missions.”