Did NASA Miss a Sign of Life on Mars 50 Years Ago?
New research suggests NASA’s Viking missions, which landed on Mars in 1976, may have detected evidence of life on the Red Planet, a conclusion overlooked for half a century. The findings are prompting scientists to re-examine data from the missions, potentially rewriting our understanding of Mars’s potential for harboring life.
The Viking program consisted of two identical American space probes, Viking 1 and Viking 2, launched in 1975. Each spacecraft included an orbiter to photograph the Martian surface and a lander to study the planet directly. The orbiters also relayed communications from the landers after they touched down.
Both Viking landers carried three life-detection experiments that yielded positive results. Although, the Gas Chromatograph-Mass Spectrometer (GC-MS), an instrument designed to detect organic molecules essential for life, did not find any. This led then-Viking Project Scientist Gerald Soffen “No bodies, no life.”
Now, a group of scientists argues that the GC-MS may have been misinterpreted, and that the positive results from the other experiments were indicative of a biological signal. The Viking 1 lander, the first spacecraft to successfully land on Mars, operated for more than six years on Chryse Planitia, performing the first Martian soil sample analysis with its robotic arm and a specialized biological laboratory, as detailed by NASA’s Viking Project overview.
The Viking missions characterized Mars as a cold planet with volcanic soil and a thin, dry carbon dioxide atmosphere, and provided striking evidence of ancient riverbeds and vast flooding. The program, which began in 1968 and was managed by the NASA Langley Research Center, exceeded its planned 90-day lifespan, with both orbiters and landers operating well beyond their initial design parameters. Viking Orbiter 1 continued for four years and 1,489 orbits of Mars, concluding its mission on August 7, 1980.
Both Viking 1 and Viking 2 were powered by radioisotope thermoelectric generators (RTGs) due to variations in available sunlight. The landers operated until November 13, 1982, and April 11, 1980, respectively. This renewed investigation into the Viking data highlights the challenges of detecting life on other planets and the importance of re-evaluating past findings with new perspectives and technologies.
