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Levin, Gilbert (1925–)





Gilbert Levin
One-time sanitation engineer in California who developed a technique to detect bacterial contaminants in water and went on to play a significant role in the Viking project as designer and team leader of the Viking labeled release (LR) experiment. In his detection method, the sample to be tested was mixed with a nutrient containing traces of radioactive carbon-14. Any bacteria present in the sample would feed on the nutrient and, as a waste product of their metabolism, give off radioactive carbon dioxide which could be detected with a radiation counter. Commercial interest in the technique proved disappointing, but then, at a cocktail party in 1959, Levin met T. Keith Glennan, NASA's first administrator. A discussion ensued about approaches to life-detection by space probes which led, in 1961, to Levin being awarded a contract to develop an instrument to search for life on Mars. Known as "Gulliver", and eventually, more formally, as the "labeled release experiment", this was to provide the most intriguing data of the three experiments making up Viking's integrated biology package. Yet, while the scientific consensus, in the wake of Viking, was that the remarkable activity found in the martian soil was of a purely chemical nature, Levin stood firm in his conviction that the data suggested a biological interpretation (see Levin's hypothesis, about the active nature of the martian soil). So strong were the disagreements between the different camps involved in the biology experiments on Viking, that the dispute became acrimonious and was the subject of two consecutive issues of the New Yorker in 1979. To this day, Levin vociferously maintains that Viking found life on Mars.


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   • ASTROBIOLOGY