Exobiology

Exobiology is the study of life outside our planet.  Exobiology has been called “a discipline in search of a subject matter”. 

Is there life beyond our planet?  A great many people believe there is, and indeed that there are millions of intelligent species out there in the vastness of the universe.  Is the universe full of civilizations?  Or are we alone? 

People have always enjoyed fanciful tales of marvelous wonders and creatures who live in lands beyond the hills, beyond the seas, and in inaccessible places like fairyland.  As the world was explored, the marvels got further away.  Lilliput did not exist.  Marco Polo’s Cathay did, but was not so impossible as it sounded at first.  Fairyland endured, but only in stories for children. 

Then, when this dreary world was deprived of much wonder, along came “science fiction”.  If we can find no more marvels on earth, we will imagine them beyond the bounds of earth.  Tolkien created a new fairyland, a version of earth in some distant past, peopled by characters who could act like adults.  The planets were populated by sentient beings on Mercury, Venus, Luna, Mars, Phobos, Jupiter, and then extra-solar places like Vega, Pern, and Andromeda.  Add the idea of “time travel” to reach other epochs as well as other places. 

As our planet was more fully explored, it seemed ever more clear that Fairyland does not exist, and is thus only the stuff of stories for children.  But beyond the earth, out into the infinite depths of the cosmos, all things seem possible. 

A great many successful “science fiction” novels were written in which adventures happen in fictional locations far enough beyond our knowledge to allow the authors to let their imaginations run free.  We see familiar names like Jules Verne, H. G. Wells, Edgar Rice Burroughs, Arthur Clarke, Robert Heinlein, Isaac Asimov, Anne McCaffrey, and many more.  Many movies were also very successful.

Somehow “science fiction” seems a less infantile genre to read than “fairy tales”, although these are often much the same.  The name “fairy tales” was replaced with “fantasy”, and in your library these works are to be found in a section labeled “Fantasy and Science Fiction”. 

People who grew up on these books are quite easy to convince that there must be millions of advanced civilizations out there.  We love the fascination found in these tales. 

On the side of skepticism, we find perhaps the first scientific argument in Fermi’s Paradox.  If there are millions of advanced civilizations out there, then some will have technology more advanced than ours.  They will come visit us, or send probes, or radio messages.  So, why have we not seen any clear evidence of visitors? 

We have begun to explore just a bit, looking for life beyond our little planet.  We found that Venus is too warm to live on.  We went to Mars, the best candidate, and not only found no Dejah Thoris, we didn’t find a single zitidar, thoat, banth, nor even an ulso; nothing but rocks and dirt.  We are reduced to a faint hope of finding whales under the ice of the oceans of Europa. 

We now have telescopes that have some chance of detecting evidence of advanced technology on other stars in our galaxy.  We have radio telescopes that ought to detect the kinds of broadcasts that we use to communicate.  So far, nothing. 

Why should we expect the existence of other civilizations out there?  The argument goes something like this:  The universe is so vast that there must be octillions of earth-like planets.  Even if the odds of developing life be very small, there must be sextillions of planets where life evolved.  Evolution, as the history of our planet shows, eventually leads to intelligent life and a technological revolution. Thus, there are quintillions of civilizations in the universe. 

So, as Fermi asked, why have we not had a lot of visits? 

Our experience on earth has shown that simple life can evolve to produce intelligence and technology.  What are the odds of evolution going this way?  We don’t know, but it seems like the chances should be good, given enough time.  Yes, it is possible that a natural disaster could wipe out life on a planet, but it would take a doozy to kill it all. 

What are the odds that life will appear spontaneously?  To be alive and able to reproduce and evolve, a creature must be able to store its design (genome) somehow.  It must be able to make copies of the genome somehow.  The genome must enable it to make copies of itself, and to extract necessary materials and energy from its environment.  It must develop all these abilities by random changes before evolution can start.  All these complex skills must come together in one object.  What are the odds that all these necessary skills will randomly occur in one place at one time?  Does it seem as if the chance that all these exceedingly improbable events would happen together would be so small that even in a trillion trials on each of a trillion planets it might never happen?  Are these odds so small that we may well be the only planet with life? 

“Contrary to the popular notion that only creationism relies on the supernatural, evolutionism must as well, since the probabilities of random formation of life are so tiny as to require a ‘miracle’ for spontaneous generation tantamount to a theological argument.”  — Chandra Wickramasinghe

If we did find life on Mars, we could then ask if it developed there or if it got there from earth.  Could a microbe have hitched a ride on a space probe?  Could a large meteor knock a contaminated bit of earth into space, where the solar wind might blow it toward Mars? 

Extraterrestrial life has attracted enough interest that it can attract funding.  This fact may be the main reason why we search. 

When will exobiology find subject matter?  I am not holding my breath.