Mars life hope again

Press, 9 August 1976, Page 8

Mars life hope again

[NZPA-Reuter Pasadena. California. ! A sample of Martian soil !in the Viking spacecraft minilaboratory has again shown tantalising activity that could be evidence of life, project scientists say. The new data were disclosed the same day that Viking 2— mother-ship and lander combined—rocketed into orbit around Mars. As in experiments a week ago, scientists in Pasadena emphasised that there were many possible explanations for the activity, and said, “We have not found life on Mars.” Dr Harold Klein, head of the Viking biology team, said, “The information does suggest at least the possibility of biological activity in the sample being incubated. The next step is to run a control test on soil that has been sterilised to exclude life.” “That test is due to be finished by August 23.

A 40-minute motor bum sent the four-ton Viking 2 soaring into its first orbit of the red planet after blasting off from Earth II months ago. It marked the first time the United States had had two probes circling another planet at the same time. After surveying terrain in the northern latitudes of Mars, Viking 2 will dispatch

its lander for a soft landing: on September 4, according to present plans. The region |i where Viking 2 will land is i believed more likely to har-i bour Martian life than the! Viking 1 landing place. Dr Norman Horowitz ruled' out the possibility that the] activity in the latest Vikingll

11 test resulted from a lifeImimicking chemical process that is believed to have caused unusual activity in a different experiment last week.

In the earlier Viking experiment, called “labelled release,” initial results seemed to indicate possible life in the soil. But in recent days scientists have been saying that the data could have

been caused by a chemical process mimicking life. That process is one in which sunlight acting on the Martian soil releases oxygen from the dirt. Ln the label-led-release test, oxygen may have eaten up a nutrient that was fed to the sample, and produced a gas waste product that resembled wastes from living organ-' isms.

Three days ago more nutrient was added to the labelled-release experiment, the scientists reasoning that if living organisms were present, an organism would continue to eat the nutrient and release gas, but Dr

: Klein said on Saturday that ■the production of gas first dropped, and then began to [increase again i “We can’t explain it yet.” I said Dr Klein. But he said I the chances were “very, [very, remote” that the [strange activity was a bio [logical process.

The Horowitz experiment involved a five-day incubation of a soil sample in simulated Martian atnios phere and sunlight The object was to see if an\

thing in the soil was using carbon from the air to produce food and growth material. On Earth, the most common example is photosynthes’s by green plants. Dr Horowitz said the

activity monitored in the experiment was roughly equal to that found in soil from dry deserts of Antarctica which harbour a small, hardy population of bacteria and algae. A rich earth sample densely populated with organisms would demonstrate a great deal more activity than that detected in the Martian soil, said Dr Klein.

Dr Horowitz said one explanation for the results of his test could be various malfunctions in the complex mini-laboratory. He said that after the control experiment was done, the original test should be repeated