'NASA rover will prove life was found on Mars 30 years ago'

Gilbert Levin, who led the "labelled release" experiment on Nasa's 1976 Viking mission to Mars, is hoping that Curiosity will find evidence proving his claim to have found carbon-based organic molecules on the planet.

The findings could reinstate his refuted theory on discovery of life on Mars, the 'New Scientist' reported.

Levin, a former sanitary engineer, led an experiment in 1976 which mixed Martian soil with a nutrient containing radioactive carbon.

His hypothesis argued that if bacteria were present in the soil, they would metabolise the nutrient and release some of the digested molecules as carbon dioxide.

The experiment found that carbon dioxide was indeed released and that it contained radioactive carbon atoms.

However, another experiment contradicted the findings.

Viking's Gas Chromatograph Mass Spectrometer (GCMS) was looking for carbon-based molecules and found none.

Nasa chiefs ruled that life could not exist without these modules, refuting Levin's findings.

"Nasa powers that be concluded that the lack of organics trumped the positive labelled release experiment," Robert Hazen, a geophysical scientist at the Carnegie Institution for Science in Washington DC said.

Since then, the team which carried out the GCMS experiment have admitted their apparatus was not sensitive enough to detect organic molecules, even in Earth soils known to contain microbes.

Now, if Curiosity does find organic molecules, Levin wants a reanalysis of his original data.

"I'm very confident that MSL (Mars Science Laboratory) will find the organics and possibly that the cameras will even see something," Levin said.

Hazen says that the claim holds some water, since it had been widely accepted that Levin's findings could only have been seen if microbial metabolisms were present in the Martian soil.

"If you can't explain that through an obvious inorganic process, then it follows that microbial life is a real possibility," he added.