NASA’s Viking was the first American spacecraft to land on Mars and returned images of craters, large volcanoes and giant canyons on the surface. In the 1970s, NASA launched two identical robots – Viking 1 and Viking 2, each equipped with landers and orbiters, to head for the Red Planet. After the mission, NASA reported that they found no signs of life. But one scientist is almost certain they may have unknowingly encountered extraterrestrial life and dismissed it, Live Science reported.
“After landing on the Red Planet in 1976, NASA’s Viking landers may have sampled small, drought-resistant life forms hidden within Martian rocks,” suggested Dirk Schulze-Makuch, an astrobiologist at the Technical University of Berlin. in an article on Big Think. He said he and his fellow scientist, Joop Houtkooper, were rethinking the results of the Viking project.
“If these extreme life forms existed and continue to exist, the experiments performed by the landers may have killed them before they were identified, because the tests would have overwhelmed these potential microbes,” Schulze-Makuch wrote, according to Live Science. He added that microbes that survive in similar conditions live on Earth and may therefore also live on Mars.
The Viking robots performed four experiments on Mars: the gas chromatograph mass spectrometer (GC-MS) experiment, for organic or carbon-containing compounds in Martian soil; The Labeled Release (LR) experiment, for testing metabolism by adding radioactive trace nutrients to soil; the pyrolytic release (PR) experiment, for carbon fixation by potential photosynthetic organisms; and the gas exchange experiment, for monitoring gases.
The results of these experiments were inconclusive. In both the LR and PR experiments, they found small changes in gas concentrations, which hinted at some metabolism taking place, and thus, possibly life on Mars. GC-MS also found traces of organochlorine compounds. However, the results were dismissed by scientists who believed that the experimental instruments had been contaminated by cleaning solutions containing chlorine. And when the gas experiment gave a negative result, the idea of Martian life was avoided once and for all.
But Schulze-Makuch thought differently because most of these experiments required adding water to Martian soil samples. Citing the 2018 study of the Atacama desert, which found microbes dying in the presence of water, he hypothesized that the use of water in these experiments should have killed microbes hiding within soil samples collected from the planet. Red.
Plus, Alberto Fairén, an astrobiologist at Cornell University and co-author of the 2018 study, told Live Science that he “strongly agreed” that adding water to the Viking experiments could have killed potential hygroscopic microbes that could have hidden signs. life on mars.
Schulze-Makuch, Houtkooper and Alberto were not the only ones who believed that life was discovered on Mars. One of the principal investigators on the NASA experiment that sent the Viking landers to Mars, Gilbert Levin, has repeatedly stated over the years that the Viking experiment detected life, according to CNN. Levin published an article in Scientific American magazine saying, “I am convinced that we found evidence of life on Mars in the 1970s.”
“NASA has already announced that its Mars 2020 Earth will not contain a life detection test,” Levin wrote, “In accordance with well-established scientific protocol, I believe an attempt should be made to conduct life detection experiments. life on the next mission to Mars possible.” He suggested that the LR experiment be repeated on Mars. “(In the 1970s) NASA concluded that LR had found a substance that mimicked life, but not life…inexplicably, in the 43 years since Viking, none of NASA’s subsequent Mars landers did not have a life-detection instrument to follow up on these exciting results.”
However, recent NASA missions have produced somewhat contradictory results. In 2007, NASA’s Phoenix spacecraft, the successor to Viking, found traces of perchlorate on Mars. Perchlorate is toxic to plant life and microorganisms. On the other hand, NASA’s Perseverance 2020 rover found organic matter on Mars, in the form of sediments that hinted at the existence of “salt lakes” somewhere on Mars. This is possible because according to NASA, Mars was a wet planet billions of years ago and had a lake. However, despite all these hypotheses, at the moment, there is no solid evidence that indicates the existence of life on Mars.