As the Inquisitr recently reported, NASA kept the scientific community on the edge of their seats in early June as it announced the first-ever discovery of complex organic molecules on the surface of Mars.
About four years prior to this amazing find by the Curiosity rover, the presence of organic molecules on the red planet was confirmed for the very first time in a drilled sample retrieved by the six-wheeled robot, notes Space.com.
But a confounding report from the New Scientist claims that the space agency may have actually come across the first samples of organic material on Mars in 1976, during the Viking exploration mission, and accidentally destroyed the evidence.
Here’s how it all went down, according to a study recently published in the Journal of Geophysical Research: Planets.
Viking 1 And Viking 2
Launched in 1975, the Viking mission entailed shipping off to Mars two pairs of orbiters and landers, which became the first-ever spacecraft to touch down on the red planet in the following year. The first lander, Viking 1, deployed on the Martian surface on July 20, 1976, the Inquisitr reported, and landed in the Chryse Planitia (“Golden Plain”).
Meanwhile, Viking 2 descended on Mars’s surface almost two months later, on September 3, 1976, and settled down at Utopia Planitia. Both these landers were sent to search for signs of microbial life but came up empty-handed.
“These experiments discovered unexpected and enigmatic chemical activity in the Martian soil but provided no clear evidence for the presence of living microorganisms in soil near the landing sites,” NASA stated in a mission overview.
According to the results, the explanation resided in the fact that “Mars is self-sterilizing,” meaning that the surface radiation and the very dry, oxidizing soil “prevent the formation of living organisms.”
Burnt By Accident
However, the new study argues that the Viking mission may have actually found organics in the Martian soil but inadvertently burned their traces when the two landers analyzed the samples.
The fact that the mission failed to detect organic material on Mars was extremely surprising, given that the red planet was known to be regularly pummeled with carbon-rich meteorites, study author Dr. Chris McKay said in a statement.
“It was just completely unexpected and inconsistent with what we knew,” said McKay, who is a planetary scientist at NASA’s Ames Research Center in California.
The new theory is that the twin landers were successful in detecting organic material on Mars but didn’t even know it because their method of analyzing soil samples by heating them to release vapors would have destroyed any possible organic molecules.
This assumption is based on subsequent findings of perchlorate salt on Mars, discovered by NASA’s Phoenix lander in 2008 and again by the Curiosity rover in 2012. This highly flammable material becomes explosive under high temperatures and could have been ignited by the gas chromatograph-mass spectrometer (GCMS) on board the Viking landers, torching any traces of organics in the soil.
The Burning Question Of Chlorobenzene
Another thing that tipped off the researchers that the Viking mission may have stumbled upon organic molecules on Mars was the chlorobenzene that turned up in the GCMS data set.
Also discovered by the Curiosity rover among the organic material recently found on Mars, this substance may have been left behind by the burning of organic molecules.
“We found evidence for the presence of chlorobenzene in Viking Lander 2 (VL‐2) data at levels corresponding to 0.08‐1.0 ppb (relative to sample mass), in runs when the sample was heated to 350°C and 500°C,” the authors wrote in their paper.
While the study lead author Melissa Guzman, from the LATMOS research center in France, is not 100 percent convinced that this discovery proves the Viking landers actually found organics on Mars and then destroyed the evidence by accident — as the chlorobenzene may have originated on Earth and contaminated the Martian soil via NASA’s research equipment, she pointed out — it is definitely a possibility worth investigating.