Did NASA’s Viking Mission Accidentally Hurt Life on Mars?
In 1975, NASA’s Viking program made history when the twin landers became the first American spacecraft to successfully reach the surface of Mars. These landers conducted groundbreaking experiments, collecting and analyzing Martian soil samples for more than six years in a quest to determine whether microbial life existed on the Red Planet. However, a provocative new theory suggests that the very methods used in these experiments may have unintentionally killed potential life on Mars.
Life detection methods under scrutiny
Dirk Schulze-Makuch, an astrobiologist at the Technische Universität Berlin, has proposed that the Viking experiments may have encountered microbes on Mars, but destroyed them by introducing liquid water. In a comment published In Nature Astronomy, Schulze-Makuch argued that Mars’ hyperarid environment, drier than Earth’s Atacama Desert, likely harbors life forms adapted to extract moisture from salts in the atmosphere. These organisms, if present, could be fatally overwhelmed by the addition of liquid water, as used in the Viking experiments.
Misplaced assumptions about water
The Viking program assumed that life on Mars, like life on Earth, would depend on liquid water. The experiments involved adding water and nutrients to the soil samples, checking for metabolic reactions. Although initial results showed potential microbial activity, they were later dismissed as inconclusive. Schulze-Makuch believes these findings could instead point to the destruction of life forms adapted to Mars’ arid conditions. He has proposed a “follow the salts” strategy, which focuses on detecting organisms that thrive in salt-driven moisture environments.
The quest for life change
Highlighting the parallels with Earth’s deserts, Schulze-Makuch pointed to evidence that microbes survive in salt-rich areas through a process called deliquescence, in which salts absorb moisture to create brine. His proposal calls for multiple methods of life detection, including AI-assisted motility analysis and advanced microscopes, to avoid relying on water-based assumptions.
This theory challenges NASA’s long-standing approach to searching for water as the key to extraterrestrial life, and pushes for a broader exploration strategy. Although controversial, it opens a critical discussion about refining techniques to uncover life on Mars.
