Viking biology experiments (1976)
July-November 1976What Happened
NASA's two Viking landers ran four experiments to test Martian soil for metabolic activity. The Labeled Release experiment produced a positive signal that looked biological. The Gas Chromatograph-Mass Spectrometer found no organic molecules, which most scientists treated as decisive against life.
Outcome
The mainstream interpretation declared Mars lifeless and sterile. Funding for Mars astrobiology collapsed for nearly two decades.
Later work showed Viking's instruments may have destroyed organics they were trying to detect, rehabilitating the question. The 2014 and 2018 Curiosity detections partly vindicated researchers who had argued organics were there all along.
Why It's Relevant Today
The TMAH result directly addresses the Viking legacy: using a chemistry method that preserves rather than destroys organics, it finds exactly what older instruments could not see.
