The Aliens Among Us (Maybe)

Water, meanwhile, is almost a miracle unto itself -- the perfect solvent, with all kinds of quirky properties that help make life possible. In fact, the report turns that statement on its head: Life on Earth uses molecular structures with properties "specifically suited to the demands imposed by water." Water is in charge. And wherever we go on Earth where there's energy and liquid water -- even miles beneath the surface, or around boiling volcanic vents at the bottom of the sea -- we find life.

More important, perhaps, life as we know it has a rather ordinary streak. All living things use mundane elements, the common stuff found all over the place: carbon, hydrogen, nitrogen, oxygen, phosphorous and sulfur. Life is small-d democratic. Maybe a life form could employ exotic elements such as platinum or uranium, but it doesn't seem necessary. Life doesn't have a taste for couture; it buys everything off the rack.

"It is chemical in essence," the report says of life, a statement that is both bland and mind-boggling. Life, you'd think, would be more than just chemicals interacting. Surely it would require some kind of special juice, energy, force. But no: Vitalism is a theory that died out a long time ago. It's just organic chemistry. It's just reactions involving polymers, covalent bonds, catalysts, solvents, nucleophiles, electrophiles.

The report by Baross and his fellow scientists is ultimately optimistic. It's almost a refutation of the "rare earth" hypothesis -- the argument that habitable planets, blessed with the right mix of elements for life and a long time for that life to evolve, are few and far between. Baross says, "We believe that astrobiology is a science of optimism. We have no idea if life exists elsewhere. We are dedicating our lives to searching for this. Why are we being driven to do this? I think it's such a fundamental question."

Paul Davies reports, "We are still completely in the dark as to whether life is a stupendous chemical fluke that happened once, or whether there is a sort of life principle (or cosmic imperative to use the words of Nobel prizewinner Christian de Duve) at work in the universe. The best (cheapest, easiest) way to settle the debate is to see whether life has started many times over on Earth."

Perhaps the search for life, and Weird Life, offers a good lesson for everyone. We all have a bad habit of tending to see only the things we expect to see. We are innately biased in favor of the familiar. "The human mind finds it difficult to create ideas truly different from what it already knows," the report states.

So look around: Do you see the world as it really is, or as you think it's supposed to be? Can you see -- with your big eyes and big brain -- what's really happening all around you?

Maybe we've found the Weird Life, and it is us.

achenbachj@washpost.com

Joel Achenbach is a Washington Post staff writer and blogs at washingtonpost.com/achenblog.