Was NASA's 'no life on Mars' conclusion in the 1970s wrong? The story of the Viking landers and their search for life on the Red Planet is a fascinating one, filled with twists and turns that challenge our understanding of the universe. In the late 1970s, NASA's twin landers, Viking 1 and 2, touched down on Mars with a mission to find signs of microbial life. The results were initially positive, but later inconclusive. NASA declared 'no life on Mars' when the landers failed to find organic molecules, which are the building blocks of life. But here's where it gets controversial: Viking did find two types of organics, methyl chloride and methylene dichloride, which are chlorinated compounds. These were at low levels, and the mission team initially thought they were contaminants from the landers. However, later rovers, Curiosity and Perseverance, also found similar organic molecules, suggesting they are native to Mars. So, if the organics were there, does that mean Viking found life after all? Astrobiologist Dirk Schulze-Makuch argues that scientists at the time were too focused on non-life explanations and should have kept an open mind about biological possibilities. He and his colleagues sent an eLetter to the journal Science, reexamining a misinterpretation published in 1976. The Viking data alone is not enough to conclude whether the landers found life or not. The results continue to be a subject of debate, and the only way to answer this question is to send a new mission to Mars specifically designed to look for extant life. This is a challenging task, but it is essential to correct an old mistake that has shaped Mars exploration for 50 years. The search for life on Mars is a never-ending journey, and we must continue to explore and learn from our mistakes to advance our understanding of the universe.
