19 Feb 2006
Rocks plus water equals life.
One might derive this equation by reading recent features on Mars or Jupiter’s moon Europa, or articles covering any of the dozens and dozens of planets discovered outside our solar system in the last decade. Find some “rocky” body, make sure there is water, and life is bound to be abundant.
We humans have this deep desire and fascination in finding life outside of earth. I mean, look how big the universe is! Life has to be thriving out there!!! And, c’mon, it is fun to imagine what it might be like. Witness the success of all those science fiction books and movies.
Well, at the risk of throwing a clinical wet blanket on the “Life Is Everywhere, We Just Haven’t Found It Yet” bandwagon, allow me to take a sober, sadly brief, and admittedly incomplete look at some more items to look for in a search for life, other than dirt and water, that is.
For example, life needs an energy source, but just the right source. A great big star throws out so much intense, nasty radiation that unless extremely well-protected, any imaginable organic life would perish. No ozone layer can shield from the death rays of the big guys.
And the big stars die very quickly – our sun would have died long ago if much bigger. Moreover, when the big ones do go, they go out with a bang and virtually sterilize any possible living quarters within light years of their death scene.
Smaller stars could provide necessary energy, but a life-support planet would have to get lethally close to the star to receive enough energy to fuel life.
Most all the extrasolar planets that have been discovered are Jupiter-like planets. That’s good… and terrible.
Good, not because the big ones can harbor life, but because little life-support planets need a big brother jovian-type planet out there to protect them from the onslaught of incoming comets and other debris. But it is a terrible thing because these big gassy guys have a really disturbing personality quirk.
Formed at great distances from their parent star, most gradually move towards the parent star. This disrupts, fatally, the orbit of any little earth-like critters in the way trying to get on with life.
For some reason our big planets stopped out there and continue today to protect us from afar.
And even if an earth-like planet were found out there somewhere some day, it has to be the right distance from its star, the right mass with the right gravity and right atmosphere covering the right multi-layered body, with the right neighbors, and with a proper moon to insure a stable rotation - all of which permit liquid water not only to exist, but to remain on a planet.
Life also needs the right place in a properly aged galaxy, the right type of galaxy, a perfectly aged and lonely star in that perfect galaxy, etc., etc. One could list literally dozens of other necessary parameters for a planet to be suitable for life – any imaginable life - but I am limited here by space and time (pun intended).
But allow me to bring in this controversial philosophical consideration: What if we found somewhere in our galaxy a perfectly pristine planet, absolutely suitable for any imaginable complex organic life? Does it follow that life automatically springs forth from this non-living orb?
Theistic scientists would say that a Supreme Being could introduce life onto a planet well suited for it. Their enjoyment comes in trying to figure out how and when He did it – those pesky and elusive details of the great mystery.
Nontheistic scientists have a more formidable order to fill – how life could spring from nonlife with no intervention. This is truly one of the Great Unsolved Problems of Science.
So far countless scientists in the last century have been unable to create even the simplest life in the lab, places which themselves represent the most pristine possible conditions for life to arise, were it able to arise by itself.
It doesn’t follow that it is impossible for life to start on its own, but the Hill of Improbabilty has thrust upward into a daunting and menacing Mountain.
Might there be life out there? I don’t know. But I do know rocks and water do not mean life.
Bottom line: Before you read an article proclaiming how the universe just has to be drowning in life, first put on your Skeptic’s Hat. Science literature is not an archive of infallible truth, this column included. And feel free to ask the tough questions. Reasoning together we can discover great truths.
That’s the beauty of science.