The Labeled Release (LR) experiment of the Viking mission to Mars in 1976 reported positive results of microbial respiration, although the majority ruled them out as a product of inorganic chemical reactions.

On July 30, 1976, the LR returned its initial results from Mars and surprisingly, they were positive.

As the experiment progressed, a total of four positive results, backed by five varied controls, came back from the two Viking spacecraft which landed on the red planet some 6,000 kilometers apart.

NASA’s Viking Project found a place in history when it became the first U.S. mission to land a spacecraft safely on the surface of Mars and return images of the surface. Two identical spacecraft, each consisting of a lander and an orbiter, were built. Each orbiter-lander pair flew together and entered Mars orbit; the landers then separated and descended to the planet’s surface. The Viking 1 lander touched down on the western slope of Chryse Planitia (the Plains of Gold), while the Viking 2 lander settled down at Utopia Planitia.

As Levin explains in an article published in Scientific American, data curves pointed to the detection of microbial respiration on the red planet. “The curves of Mars were similar to those produced by the LR tests of soils on Earth. It seemed that we had finally answered the ultimate question,” he says.

However, when the Molecular Analysis Experiment was unable to detect organic matter, the essence of life, NASA concluded that the LR had probably found a substance that mimicked life, but itself was not life. “Inexplicably,” says Levin, “during the 43 years since Viking, none of NASA’s subsequent Mars landers have carried a life-detection instrument to track these exciting results. Instead, the agency launched a series of missions to the red planet to determine if there was ever a suitable habitat for life and, if so, eventually bring samples to Earth for biological testing.”

In his view, NASA’s reservation against the direct search for microorganisms ignores the simplicity of the task carried out by Louis Pasteur in 1864. This famous French chemist and bacteriologist allowed microbes to contaminate a hay-infusion broth, after which bubbles of their expired gas appeared. Before containing live microorganisms, no bubbles appeared. (Pasteur had previously determined that heating, or pasteurizing, such a substance would effectively kill microbes.)

It is this simple test, updated in order to replace modern microbial nutrients with the hay-infusion products in Pasteur’s, is in daily use by health officials across the world to analyze potable water. Billions of people are thus protected against microbial pathogens.

Essentially, Levin explains, this test was the LR test on Mars, adjusted by the addition of several nutrients considered to broaden the possibilities for success with alien organisms and the tagging of the nutrients with radioactive carbon. These simple changes made the LR experiment sensitive to the extremely low microbian populations postulated for Mars, should they exist.

“But on Mars,” he adds, “each LR experiment continued for seven days. A heat control, similar to Pasteur’s, was added to determine if any response obtained was biological or chemical.”

The Viking LR experiment attempted to detect and monitor the ongoing metabolism, a very simple and false-positive indicator of living microorganisms. Several thousand executions were carried out, both before and after Viking, with terrestrial soils and microbial cultures, both in the laboratory and in extreme natural environments. No false positive or false negative results were obtained.

Levin assures that “this strongly supports the reliability of the LR data obtained on Mars, despite the explanations later postulated by NASA.

The former NASA scientist goes on to add that in addition to the direct for life on Mars obtained by the Viking LR, evidence supportive of, or consistent with, extant microbial life on Mars has been obtained by Viking, subsequent missions to Mars, and discoveries on Earth among which are the following:

Scientific missions such as Viking, Pathfinder, Phoenix, and Curiosity all discovered sufficient surface water to sustain microorganisms on Mars.

Both the Phoenix and Curiosity missions have discovered evidence that the ancient environment on Mars was most likely habitable.

NASA’s Curiosity mission has reported the discovery of complex organics on Mars, possibly including kerogen which may be of biological origin.

Scientists have reported an excess of carbon -13 over carbon-12 in the Martian atmosphere, a feature indicative of biological activity.

Experts have also discovered that the Martian Atmosphere is in disequilibrium. According to experts, Martian C02 should long have been converted to CO due to the Sun’s UV light. This means that the CO2 is being regenerated, possibly by microorganisms on the planet.

Microorganisms can survive extreme conditions. In fact, terrestrial organisms have somehow managed to survive in outer space, outside the International Space Station.

Lare amounts of methane have been detected on Mars and scientists say that microbial methanogens could be the source.