Cosmos - Carl Sagan [67]
But what is the optimum way, given severe constraints on size, cost and power requirements, to search for microbes on Mars? We cannot—at least as yet—send microbiologists there. I once had a friend, an extraordinary microbiologist named Wolf Vishniac, of the University of Rochester, in New York. In the late 1950’s, when we were just beginning to think seriously about looking for life on Mars, he found himself at a scientific meeting where an astronomer expressed amazement that the biologists had no simple, reliable, automated instrument capable of looking for microorganisms. Vishniac decided he would do something about the matter.
He developed a small device to be sent to the planets. His friends called it the Wolf Trap. It would carry a little vial of nutrient organic matter to Mars, arrange for a sample of Martian soil to be mixed with it, and observe the changing turbidity or cloudiness of the liquid as the Martian bugs (if there were any) grew (if they would). The Wolf Trap was selected along with three other microbiology experiments to go aboard the Viking landers. Two of the other three experiments also chose to send food to the Martians. The success of the Wolf Trap required that Martian bugs like liquid water. There were those who thought that Vishniac would only drown the little Martians. But the advantage of the Wolf Trap was that it laid no requirements on what the Martian microbes must do with their food. They had only to grow. All the other experiments made specific assumptions about gases that would be given off or taken in by the microbes, assumptions that were little more than guesses.
The National Aeronautics and Space Administration, which runs the United States planetary space program, is subject to frequent and unpredictable budget cuts. Only rarely are there unanticipated budget increases. NASA scientific activities have very little effective support in the government, and so science is most often the target when money needs to be taken away from NASA. In 1971 it was decided that one of the four microbiology experiments must be removed, and the Wolf Trap was off-loaded. It was a crushing disappointment for Vishniac, who had invested twelve years in its development.
Many others in his place might have stalked off the Viking Biology Team. But Vishniac was a gentle and dedicated man. He decided instead that he could best serve the search for life on Mars by voyaging to the most Mars-like environment on Earth—the dry valleys of Antarctica. Some previous investigators had examined Antarctic soil and decided that the few microbes they were able to find were not really natives of the dry valleys, but had been blown there from other, more clement environments. Recalling the Mars Jars experiments, Vishniac believed that life was tenacious and that Antarctica was perfectly consistent with microbiology. If terrestrial bugs could live on Mars, he thought, why not in Antarctica—which was by and large warmer, wetter, and had more oxygen and much less ultraviolet light. Conversely, finding life in Antarctic dry valleys would correspondingly improve, he thought, the chances of life on Mars. Vishniac believed that the experimental techniques previously used to deduce no indigenous microbes in Antarctica were flawed. The nutrients, while suitable for the comfortable environment of a university microbiology laboratory, were not designed for the arid polar wasteland.
So on November 8, 1973, Vishniac, his new microbiology equipment and a geologist companion were transported by helicopter from McMurdo Station to an area near Mount Balder, a dry valley in the Asgard range. His practice was to implant the little microbiology stations in the Antarctic soil and return about a month later to retrieve them. On December 10, 1973, he left to gather samples on Mount Balder; his departure was photographed from about three kilometers away. It was the last time anyone saw him alive.