NASA's Viking Landers Found Potential for Past Martian Life 50 Years Ago But May Have Resulted in Accidental Extinction

A researcher is reiterating the notion that life on Mars might have been discovered and inadvertently eliminated five decades ago. The Viking missions, initiated in the 1970s, were pioneers in Martian life exploration; despite inconclusive outcomes, they indicated no signs of life. Astrobiologist Dirk Schulze-Makuch suggests reevaluating those initial findings, considering the increased knowledge about Mars.

NASA's Viking Landers Found Potential for Past Martian Life 50 Years Ago But It May Have Resulted In an Accidental Extinction Unsplash/Planet Volumes

Testing for Alien Life on Mars

Schulze-Makuch from Technical University Berlin said that the Viking Labeled Release experiment initially yielded signs of metabolism, but later investigations found no organic traces. Schulze-Makuch suggests that excess water in the soil's nutrient solution might have led to the demise of potential life forms.

This theory is paralleled by the survival of microbes in Atacama salt rocks, indicating the potential danger of excessive water for Martian organisms.

NASA's Viking mission successfully landed two landers on Mars in 1976, namely Viking 1 on July 20 and Viking 2 on September 3. These landers were equipped with various instruments like gas chromatograph/mass spectrometer, X-ray fluorescence spectrometer, seismometer, meteorology tool, and stereo color cameras.

The Viking landers carried instruments for investigating life indicators, soil properties, and atmospheric characteristics on Mars. In an op-ed for BigThink, Schulze-Makuch discussed the perplexing Viking results: one test yielded a positive response, another showed negative gas exchange, and trace amounts of chlorinated organics were detected.

The life-positive test introduced water to the soil to detect signs of respiration and metabolism. The hypothesis was that potential Martian microorganisms would consume nutrients, emitting radioactive carbon as gas if present.

Viking Experiments May Have Overwhelmed Potential Microbes on Mars

A 2007 experiment incorporated hydrogen peroxide into cells of suspected Martian life, which would provide benefits in Mars' environment. Schulze-Makuch wrote that this adaptation could clarify the Viking results, as hydrogen peroxide in cells could have led to their demise and the formation of detected carbon dioxide.

Another experiment, pyrolytic release, indicated potential organic synthesis. While Viking detected chlorinated organics, the possibility of terrestrial contamination from the landers was considered.

There was a suggestion that the landers could have introduced Earthly contaminants. However, subsequent missions confirmed the existence of native organic compounds on Mars. Schulze-Makuch speculated that Martian life might have adapted to survive within salt rocks, absorbing water from the atmosphere.

The Viking experiments, involving soil-water interactions, might have overwhelmed these microbes, leading to their potential extinction. Despite ending their active missions in the 1980s, both Viking landers remain on Mars.

Efforts to find extraterrestrial life aim to enable human interplanetary existence, with Mars being a prominent contender. The Perseverance rover, currently operational on Mars, contributes to this goal by partnering in an international endeavor to explore the planet.

In 2028, a Sample Retrieval Lander is anticipated to launch, carrying a Mars rocket and helicopters, positioned near the rover to collect Mars samples, ensuring a close distance of about 66 yards (60 meters).