Viking: The First Signs of Life?

It was an electrifying announcement. At a hastily called press conference at the Jet Propulsion Laboratory in Pasadena, Calif, last weekend, Viking Scientist Harold Klein reported that the newly begun biology experiments aboard the Mars lander had already shown a strange process--perhaps life--going on in the Martian soil. Said Klein: "We have at least preliminary evidence of a very active surface material. It looks at first indication very much like biological activity."

The evidence that excited Viking scientists came from two of the three biological tests that had begun only three days earlier. One of the Viking experiments, designed to detect respiration, showed that 15 times as much oxygen as the scientists expected had come from the Martian soil sample. The other, which uses radioactive tracers to look for signs of metabolic activity, showed what Klein called "a very strong, positive response." Said a Viking spokesman: "If there is life on Mars, this is what it should be doing."

Viking scientists cautioned that more tests are necessary; the oxygen might simply have been released from some mineral in the soil sample when it was placed in the heated experiment chamber, and the radioactive gases produced in the other test might have been caused by an oxidation process not connected with life. Still, said Klein, "if it is a biological response, then it is a stronger response than we have seen in fairly rich terrestrial soil, and it would also imply that microbal life on Mars is highly developed--more intense than it is on earth."

At one point early in the eventful week, it had been so quiet at the Jet Propulsion Laboratory that scientists could hear a pin drop. Then, 214 million miles away, a pin did drop--onto the reddish soil of Mars. It fell from Viking, freeing the mechanical arm that it had jammed and enabling the lander to begin its historic life-seeking experiments. Some 19 minutes later, as telemetry confirming that the arm was no longer jammed appeared on the console screens at JPL, scientists and engineers broke into cheers. Said Meteorologist Seymour Hess: "Happiness is a functioning instrument in a spacecraft."

Three days later, shortly after Martian sunrise, Viking reached out with its arm, scooped up a sample of Martian soil and dumped it into the craft's biological laboratory. Scientists first learned that the arm was working from a picture transmitted from the lander. The shot showed a footprint-like trench about 6 1/2 in. long, 2 1/2 in. wide and 2 in. deep that had been scooped out by Viking. Scientists were struck by the fact that the sides of the trench had not collapsed. Said Princeton University Geologist Robert Hargraves: "It's strange material. It looks and acts like wet sand."

Nearly two hours later, Viking signaled that a xenon lamp, which simulates Martian sunlight in one of the biology experiments, had turned on. This confirmed that the arm had delivered soil to the laboratory and that the biology experiments had started. The first experiment--a search for evidence of the life process called photosynthesis--was under way. The photosynthesis experiment, plus the two that showed the unexpectedly early results, will take twelve days to complete. Furthermore, the tests will have to be repeated before Viking biologists can draw any firm conclusions about the existence of life in the particular soil that the spacecraft has sampled.

Reddish Hue. Viking's mechanical arm also delivered soil, scooped from the same trench, to an inorganic chemical analyzer, which will determine the elements in the material. The inorganic chemistry lab's first findings showed that the soil sample contains calcium, silicon, titanium, aluminum, iron and the iron oxide responsible for the reddish hue of Mars. But Viking's arm may have failed to make delivery to still another miniature laboratory, an organic chemistry analyzer designed to look for evidence of past Martian life. After two attempts, telemetry showed that soil had apparently not reached the interior of the lab.

If Martian life is discovered, Project Scientist Gerald Soffen speculates, it will probably be quite different from anything found on earth. Martian organisms are likely to be microscopic in size. They would also have to be capable of extracting life-giving moisture from the planet's arid soil and atmosphere. Soffen believes they might do this by means of some sort of biological pump or natural siphon. "Martian critters have had billions of years to adapt," he explains. Somewhere in the process of evolution they must have had to face--and overcome--the need for water. "So what they developed is something called a water pump," theorizes Soffen. "They found a way to pump water out of the atmosphere." Not long ago, Soffen's speculation might have seemed far out. But in light of last week's dramatic announcement, it may well be closer to fact than fantasy.

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