VIking 1 did find evidence of extraterrestrial microbes in soil samples from the Red Planet.
Mathematical analysis of the samples concluded that salts in the soil on Mars ‘threw off’ initial estimates – and that the soil samples show strong evidence of microbial life.
The new analysis looked for ‘complexity’ in the samples – an indication of life. To the surprise of the scientists, they found it.
‘This suggests a robust biological response,’ say the researchers, from the University of Siena and California’s Keck Institute.
‘These analyses support the interpretation that the Viking LR experiment did detect extant microbial life on Mars.’
The reassessment was prompted by the discovery of ‘perchlorates’ in the soil at the landing site of another Mars lander, Phoenix, in 2008.
The presence of the chemicals in Viking’s samples had led scientists to conclude the samples were contaminated.
The scientists behind the experiment remain divided over how conclusive the evidence for life on Mars is.
Christopher McKay of Nasa’s Ames Research Centre said, in an interview with Discovery News, ‘Finding organics is not evidence of life or evidence of past life. It’s just evidence for organics.’
‘The ultimate proof is to take a video of a Martian bacteria. They should send a microscope — watch the bacteria move,’ said Josheph Miller of USC’s Keck School of Medicine.
‘On the basis of what we’ve done so far, I’d say I’m 99 percent sure there’s life there.’
Future Mars missions may be able to settle the question.