NASA’s Viking missions to Mars in 1976 may have stumbled upon signs of life, and a new wave of scientists is looking to challenge the long-held belief that Mars is barren. The Viking 1 and 2 landers carried several experiments to detect life, and although some initial tests hinted at potential signs, the conclusion was that Mars was lifeless due to a lack of discovered organic molecules.
Gerald Soffen, the Viking Project Scientist, famously stated, “No bodies, no life.” However, recent arguments from Steve Benner, a chemistry professor at the Foundation for Applied Molecular Evolution in Florida, suggest a different story from the data collected during these missions.
Benner pointed to the Gas Chromatograph-Mass Spectrometer (GC-MS) used in the Viking missions, which detected unexpected bursts of carbon dioxide and trace amounts of methyl chloride instead of organic molecules. This led many to conclude that Martian soil was devoid of life. Yet, Benner argues that the GC-MS did, in fact, reveal organic molecules, just in different forms than expected.
Scientists have since found organic materials on Mars, including those linked to meteorites, but the Viking results remain puzzling. They did not seem to align with the notion that these compounds had been destroyed by a powerful oxidant. However, in 2008, NASA’s Phoenix lander discovered perchlorate on Mars’ surface, which can degrade organics. This could explain why Vikings didn’t identify the expected organic molecules.
Furthermore, Benner references work done in 2010 by NASA astrobiologist Rafael Navarro-González, which showed that the interaction of organics with perchlorate produces byproducts including methyl chloride and carbon dioxide. This potentially clarifies the unexpected findings during Viking’s tests, as the GC-MS didn’t miss out on detecting life; it documented the life’s degradation products instead.
The implications of these findings are profound. If the Viking landers did find microbial life, it shifts the understanding of Mars significantly. Benner and his team even propose a model for what these Martian microorganisms could look like, calling it the BARSOOM model, which envisions bacteria that can produce and store oxygen.
Interestingly, the discussion around this research has heated up recently, particularly on social media platforms where users express both skepticism and excitement over the prospect of life on Mars. This debate highlights how scientific understanding can evolve over time and emphasizes the importance of ongoing exploration and data review.
As the Viking missions celebrate their 50th anniversary, Benner urges for an open dialogue around these findings. He believes that this could mark a new beginning in the quest for understanding life on Mars and possibly rekindle interest in such explorations. With every new discovery, the dream of uncovering life beyond Earth inches closer to reality.
For a deeper dive into this research, you can explore the publication in the journal Astrobiology.
