How the NASA Viking Rover May Have Discovered Life on Mars 40 Years Ago

Life on Mars may have been discovered earlier than humans have ever imagined. A recent study says that the scientific community might have overlooked the findings of two NASA probes, Viking 1 and Viking 2, that landed on Mars in 1976.

The study, published in the journal Astriobology, reveals that the Viking experiments 40 years ago could have stumbled signs of life on Mars. The Viking robots were sent to Mars to study the red planet's biological make-up.

"We long ago pointed out the problems with the Viking GCMS (gas chromatograph -- mass spectrometer). Even its experimenter, Dr. Klaus Biemann, often stressed that the GCMS was not a life-detection experiment," explained Gilbert Levin, one of the study's authors via Phys Org. "It required at least one million microbial cells to detect any organic matter. In addition, the instrument had frequently failed when tested on Earth. Later, it was claimed that perchlorate in the soil destroyed the organic matter. However, I view this cautiously as there is no evidence for perchlorate at the Viking sites."

Levin from Arizona State University and Patricia Ann Straat from the US National Institute of Health proved this claim by studying the Martian soil discovered by the Viking probes, To prove that the Martian soil might contain signs of life, the researchers mixed it with nutrient-rich water. The idea is if there are living things in the soil, they would metabolize the nutrients from the water.

Upon mixing the Martian soil with the nutrient-containing water, results showed that the microbes in the soil metabolized the nutrients, releasing radioactive molecules, CS Monitor reports.

"You may not agree with the conclusion, but you cannot disparage the steps leading there. You can say only that the steps are insufficient. But, to us, that seems a tenuous defense, since no one would refute these results had they been obtained on Earth," Levin said.

The experiments on the Martian soil obtained by the Viking probes could be the most "pristine" Martian life detection we could ever obtain as the landers that followed the Viking experiments could have already contaminated Martian soil. The researchers said that conducting "carefully designed" experiments could lead to answers about life on Mars.