If the odds of evolution having occurred on our planet were that minute, one in a trillion or whatever, why are we looking for a second occurrence?

Corzine, evolution is a process, not an end product.  Evolution will occur wherever there is life, because conditions on planets are always changing.  Those changes will cause successive generations of organisms to evolve traits that favor survival.  So I think that your imaginary "odds" must refer to the likelihood of our kind of intelligent life evolving on such a planet.  Given that our planet did not have human life for about four billion years, and humans have only been around for about 200,000 years, it very unlikely that such a planet would would have reached a state where our kind of intelligence would have evolved.  In fact, intelligent life may be fairly rare in the universe.  Nevertheless, given that there are roughly 1,000,000,000,000 stars in our galaxy and about the same number of galaxies as stars in our galaxy, the likelihood that intelligent life has evolved in other solar systems is probably extremely likely.  We will probably never encounter it as long as our species survives, but there is always hope.

Do we think that the odds are better there?  Because if not, we're wasting a lot of money looking for something that has a 1 in 100000000000 or whatever chance of being the case!

Scientific research is not necessarily done to achieve a practical result.  Its purpose is to increase our knowledge of the reality we find ourselves in.  Sometimes, our increased knowledge leads to very practical results.  Einstein did not set out to invent atom bombs or nuclear reactors, but his discoveries led to the practical inventions.  What we stand to gain from space exploration is very practical--perhaps a way to export our form of life elsewhere in the solar system or even outside the solar system.  After all, the purpose of all life is to survive, so securing survival for our progeny is one of our most important goals.  If we find habitable planets that we can adapt earthlike organisms to, then we may be able to colonize other planets.  Even if not, though, we might learn some very practical things about the way life can evolve in strange environments.

Is it really a useless search?  It is almost certain that other intelligent life existed in the past, and it is one of the great questions that people have asked.  Are we alone in the universe?  After all, for millenia, religion has taken the position that we (the tribe, the nation, the empire) were special in the eyes of those who created the universe.  Now that we know something about the vastness of the universe, it is reasonable to search for others that might contribute to our knowledge.  More importantly, though, is that the search for alien life (not necessarily intelligent life) will tell us new things about our own origins.  Religion has certainly failed to predict the extent of the universe that science has discovered.

As for processes and "end products", it is important to remember that evolution has no fixed direction.  It is just a process whereby successive generations grow into the forms that a changing environment kills off less quickly.  Intelligent life exists on earth because it proved survivable in the present geological epoch.  Let's hope that it continues to survive, despite the coming changes.

You won't get an argument from me about the importance of science.  You can spare your diatribe against the church!

Sorry for the jabs at religion, Corzine, but I still feel the point worth making that all religions have creation myths.  Science has proven its worth as a better alternative to answering questions that religions have gotten wrong.

I think that we got onto the whole "end products" thing because I was talking about an "occurrence" of evolution that produced intelligent life here.  What if I just rephrase, and say that it's too unlikely that we will find another planet where evolution has taken a similar direction and is in a similar phase.

And I would submit that finding planets in which evolution has taken different directions will be far more interesting.  It would revolutionize our knowledge about biology and possibly lead to even greater breakthroughs in medicines.

I mean that that search for intelligent life is (virtually) useless because it is so incredibly unlikely that we will ever find any.  Literature has also been an undeniable enrichment to our society, and continues to be.  The same reasoning would put those proverbial monkeys on the typewriters, in hopes that one of them would turn out an award winning novel (or maybe directions to that planet!).

The discovery of intelligent life elsewhere in the universe, however unlikely, would be a scientific bonanza for us.  It would have the potential of advancing science to the point where we might be able to escape our inevitable demise on this planet.  That alone is worth the search.  But the discovery you cited in the OP had nothing to do with SETI.  It was just about finding habitable planets outside of this solar system.  From that kind of knowledge, we might be able to make better estimates of how likely it is that we will find intelligent life elsewhere.  Also, there is always the potential for colonization of other planets, even though the means to do that now seem well beyond our powers. 

There is an element of unreasonableness that drives those scientists who search for intelligent life.  As great as the fruit of success would be, the fact is that not one of them can expect to succeed.  They are fighting against all odds, so to speak.

Again, I think that you have mixed up the search for intelligent life with the search for any life.  SETI is another matter, and I am more inclined to agree with your pessimism on that score.  Just the same, it is very much worth the effort.  It's a very long shot, but maybe we'll get an answer to Fermi's Paradox.  If intelligent life exists in the universe, why hasn't it found us already?  The depressing possibility is that all or most cases of intelligent civilizations only exist for a short time before they pollute themselves out of existence.  That seems to be the direction that we are going in.

Ha!  I meant that I am not your enemy regarding science; I did not mean to imply that I agreed with you regarding so-called "creation myths!" 

I know, but you cannot deny the truth of what I said. 

As regards SETI and looking for habitable planets, I submit a google news link: http://news.google.com/?ncl=1115688836&hl=en  It is clear that the two searches are very closely connected in the minds of the scientists.  I didn't make the SETI stuff up.

My point was that you confused them, as you do again here.  The connection is very asymmetric.  SETI enthusiasts are naturally interested in proving that other planets are habitable, but planetologists do not necessarily care about finding intelligent life.  this discovery was not caused by the search for intelligent life, just earthlike planets.

Again, a scientific bonanza it may be, but it's not worth the opportunity cost!  That's like paying a million dollars for a ferarri when a porsches are a dime a dozen...literally!  Sure, it'd be great to have.  But is it really worth it?  That's time and energy and minds spent on a million to one chance -- not because it's impossible, but because it's a search...one at a time for one in a trillion!

Seems silly to me.

I know, and I regret that.  Pure scientific research is worth pursuing, because it enables the more practical discoveries, not to mention that it is just worth satisfying our curiosity about the universe.  The time and energy spent is a drop in the bucket when compared to, say, the time and energy spent on the cosmetics industry, fast food sales, or building up war machinery.  This attitude that we should not pursue science unless it has a proven benefit ahead of time is why the US is falling behind European and Asian countries, which have no such qualms.  We used to lead the world in physics research, but we are now heading in the opposite direction, because Congress can't see the point in building a particle accelerator that could finally bring us a comprehensive understanding of nature's forces.  But what the heck.  At least, somebody is working on it.  The US has had a good run, and it may be time to step aside and let bolder countries move past us.

Corzine,  thanks for your response.  I think that we have quite a disagreement on the nature and value of what planetologists do.  Among other things, they help us to understand what is happening to our own world.  So, unlike you, I think that their research goals have a great deal of relevance and are well worth the small effort and resources that we devote to them.  Just my opinion.

Sntjohnny, the interesting thing about the discovery was that it does not appear to be any kind of Venusian hell hole.  Rather, it appears to have an atmosphere in which liquid water can exist, and therefore life as we know it.  If the odds are so great against the existence of earthlike planets, then one would not expect us to find one so easily--just as we are beginning to perfect techniques for discovering planets in other star systems.  So perhaps our calculations about the rarity of earthlike worlds have been overly pessimistic.

Bear in mind that, however rare it is for a world to develop intelligent life as ours did, we should be more surprised not to find ourselves in such a rare location than in one that is hostile to our form of life. 

That was a test to see if you were awake, sntjohnny.  Apparently, I was not.   

The planet falls within the star's temperate zone, which means that the climate may be temperate enough to have running water on its surface, as does our planet and Mars.

Now Mars has running water on it too?? Full marks for having a vivid imagination, Cop!

Come on, 8d8, keep up with the news.  This was reported last year:  http://www.csmonitor.com/2006/1207/p01s02-usgn.html

They have located more planets in the red dwarf solar system, but they are likely gas giants.  It is quite possible that the so-called "earthlike" planet doesn't have running water.  At this point, the exciting news is that it is a rocky planet not too much larger than our own and orbiting within a zone that could give it moderate temperatures.  Scientists are working on ways of detecting biological activity through chemical signatures, but we don't have the capability for that yet.

It is still possible that we will discover signs of life on Mars, since it once did have more water.  Titan is particularly interesting.  Although it is too cold and too hostile to sustain our kind of life, it has a lot of complex climate activity.  If life evolved from complex self-replicating processes, then Titan may provide some clues as to how it originally evolved on earth.

On the possibility of still finding "life" on Mars - I think you'll still get better odds on WMD in Iraq
If life evolved from complex processes here on Earth, as you still speculate it did, why not then "next door?" on Mars as well? After all, it's orbiting the exact same star and had plenty of water? Strange...

Why not, indeed?  I think that the jury is still out on whether or not we will find signs of historical (or even modern) life on Mars.  You act as if the question had already been answered, but I wouldn't be so quick to offer odds on the possibility at this point.