Accepted Notion of Mars as Lifeless Is Challenged

For all the triumph of NASA’s 1976 Viking mission, which put two unmanned spacecraft on Mars, there was one major disappointment: The landers failed to find carbon-based molecules that could serve as the building blocks of life.

The complete lack of these organic molecules was a surprise, and the notion of a desolate, lifeless Mars persisted for years.

Now, some scientists say that conclusion was premature and perhaps even incorrect. They suggest that such building blocks — known as organic molecules, although they need not come from living organisms — were indeed in the soil, but that they were inadvertently destroyed before they could be detected.

If true, that could cast the scientific conclusions of the Viking mission in a new light, especially since another Viking experiment claimed to have found living microbes in the soil. Most scientists discounted that possibility — how could there be life in soil devoid of the building blocks of life?

“That gospel of the Viking results has influenced our perspective on life of Mars for 35 years,” said Christopher McKay, a planetary scientist at NASA’s Ames Research Center in California and an author of the new findings, to be published in The Journal of Geophysical Research — Planets. “What do they find? Nothing. But it turns out it was not really nothing.”  Read Article

By Kenneth Chang