In an interesting piece in the Washington Post, Joel Achenbach states up front,
Martian life is awfully cryptic. That’s a scientific term: It means life that is out of sight, below the surface, burrowed into ecological niches not easily scrutinized by robotic sentinels from the planet Earth.
Or perhaps it’s not anywhere. Mars may be dead as dead can be.
Going back to the 19th century, a persistent feature of hypothetical Martian life has been the way it has bewitched and teased earthlings but then refused to materialize. Time and again, scientists have detected signatures of Martian life, only to discover that they were written in vanishing ink.
The Curiosity Rover did not detect methane in Mars’ atmosphere, hence the Monday morning assessment quoted.
His good overview article makes clear, however, that the search for extraterrestrial life is driven by a psychological need, and no disappointment really matters.
As Tom Bethell put it in 2007,
Some of us want to believe in extraterrestrials because an article of our secular faith holds that there is nothing exceptional about human life. This is dogma, lacking any justification, but it has already been codified as the Mediocrity Principle. The Earth, life, mankind, and civilization are humdrum, routine developments; nothing out of the ordinary about them. And if that is so, we should expect to find such life all over the Galaxy.
To most people, it would make no difference if we don’t find any such thing, but
The longshoreman philosopher Eric Hoffer — he worked on the San Francisco docks for 25 years — noted that intellectuals of the past century had done all in their power “to denude the human entity of its uniqueness”; to demonstrate that we are “not essentially distinct from other forms of life.” He contrasted Pascal’s comment that “the firmament, the stars, the earth are not equal in value to the lowest human being,” with that of “the humanitarian” Bertrand Russell: “the stars, the wind in waste places mean more to me than even the human beings I love best.” Somehow, we take that as a sign of our maturity. Our philosophers want to rub our noses in the dust. Thou art dust!
That’s what’s really at stake here.
Sometimes, it takes a comic turn: Achenbach recounts,
Seth Shostak, senior astronomer at the SETI Institute, related one of the many false-start Martian-life stories: In 1928, when Mars and the Earth came unusually close to one another, some people in the United States got the notion that anyone with a radio transmitter should turn it off. The radio silence would presumably make it easier to detect any radio signals coming from a civilization on Mars.
In fact, some people did detect radio signals coming from somewhere out there. Explained Shostak: “They weren’t actually Martians. They were merely Canadians.”
But that means there’s hope, see?!! Francis Collins and Karl Giberson know how Canadians can become an extraterrestrial separate species. It’s just that they’ve been hard to motivate, that’s all.