If Phoenix Finds Life on Mars, Do You Cheer or Cry?

As NASA's Phoenix Mars-craft begins to do its job in earnest, the global conversation is heating up about whether it's good news or bad news to discover life on other planets. The Economist starts with the premise that we'll be disappointed if Phoenix can't find signs of life -- and that it's unfortunate that a concurrent Harvard paper concludes that Mars probably never had the kind of water that could support life.

On the other hand, Nick Bostrom, who heads the Future of Humanity Institute at Oxford University, writes that finding life on Mars would be the worst news ever. No headline would ever spell more disaster, he insists in an argument that, actually, I don't quite buy. Has to do with what he calls The Great Filter making sure civilizations never advance far enough to colonize space.

To understand the strange push-pull humans feel about the possibility of extraterrestrial life, just look at the movies. You've got your Independence Day type of movies, where the aliens are the Conquistadors and humans are the Mayans. And you've got your Close Encounters of the Third Kind type of flicks, where the aliens are enlightened beings stopping by to say hello.

Finding other life -- knowing we're not alone in the universe and that our species might survive beyond Earth -- seems comforting in a way. But it's one thing to find evidence of a few microbes and another to learn that there's a race of beings out there that makes us look like technological infants. At least on our planet, the history of first encounters between the technologically advanced and the technologically primitive is that they do not generally go well for the technologically primitive.