The idea of life on Mars has fascinated scientists for decades. In the 1970s, NASA’s Viking missions made history as the first to land on the Martian surface with the goal of finding signs of life. However, a new hypothesis is challenging the very premise of those missions. Astrobiologist Dirk Schulze-Makuch now suggests that the Viking landers may have unintentionally destroyed any potential life forms on Mars by introducing water into the environment, upending the traditional belief that liquid water is essential for life.
NASA’s Viking missions, launched in the mid-1970s, aimed to answer a simple question: Does life exist on Mars? Viking 1 and Viking 2, which landed on Mars in 1976, conducted experiments to detect biological activity by exposing Martian soil to water and nutrients. The assumption was that life, if it existed, would respond in a way similar to life on Earth. While the experiments produced some intriguing reactions, the results were later dismissed as false positives, and most scientists concluded that the missions did not uncover evidence of life.
Fast forward nearly 50 years, and Schulze-Makuch’s theory (via Space.com) challenges these findings. He argues that the water used in the experiments may have disrupted potential Martian life, particularly microbes adapted to the planet’s dry conditions. Mars is known for its hyperarid environment, and any microbial life forms could have evolved to draw moisture from the thin atmosphere instead of relying on liquid water. Schulze-Makuch likens the impact of the Viking landers to the 2015 incident in Earth’s Atacama Desert, where an influx of rain caused a dramatic drop in microbial populations. According to him, the Viking missions may have caused a similar effect on Martian microbes, inadvertently flooding the environment with moisture they could not survive.
This hypothesis challenges the long-standing “follow the water” approach used in NASA’s Mars missions. Schulze-Makuch proposes that future searches for life should focus on hygroscopic salts- compounds that absorb moisture from the air – as potential habitats for microbial life, rather than only looking for liquid water. He believes this shift in strategy could help scientists uncover life forms that have adapted to Mars’ extreme dryness.
As the search for life on Mars continues, Schulze-Makuch’s hypothesis opens up new avenues for exploration. Rather than simply assuming that liquid water is the key to detecting life, future missions may need to reconsider how life could survive in the planet’s harsh conditions. With new technologies and methods, scientists may soon be better equipped to uncover the truth about life on Mars- if it ever existed.
