The Search for Extraterrestrial Life - A Quest of Faith?

Fine-grained mudstone on Mars, courtesy NASA

The New York Times declares, "Mars Could Have Supported Life Long Ago, NASA Says," yet look at all the unknowns mentioned right at the top of the article (emphasis added):

Several billion years ago, Mars may well have been a pleasant place for tiny microbes to live, with plenty of water as well as minerals that could have served as food, NASA scientists said Tuesday at a news conference on the latest findings from their Mars rover. But they have yet to find signs that actual microbes did live in that oasis.

What is it that keeps the these scientists going despite the lack of proof? It appears to be faith. My science fiction novel, Beyond Earth, explores this, following a scientist who is "certain life is out there, somewhere." At one point, he complains to a colleague:

--The universe is so big, I could go on searching my whole life and never run across the proof. That is... proof to convince the skeptics. I feel like Schiaparelli seeing canals on Mars; or worse, some UFO cultist who, when confronted with the lack of proof, says "But that just shows how good they are at covering it up."

Consider how faith-like the search for extraterrestrial life can be:

• There is no experimental proof of it.
• There is no historic evidence of it.
• There is nothing known for certain about its form or nature.
• Its supporters persist despite a lack of positive evidence.
• Any evidence to the contrary is interpreted by the dogma rather than calling the dogma into question.
• Only a universal negative would be accepted as proof that it does not exist.

Some day we may find life on other planets. But is it from other planets? I'm sure that will be debated. In the meantime though, it appears to remain a quest of faith.