Okay, maybe that was a stupid statement; y'all two seem to think it was. What should the expectation for finding life be?
To me the issue is the infinitesimally small amount of planets we have data on compared to the number that likely exist, tens of billions of earth like planets by some calculations, making it beyond too early to draw conclusions.
I agree with Desk trauma, public hermit.
But let me be wordier. I think there are two implied issues here: 1) the likelihood of life in the universe, and 2) the likelihood of finding it.
We don't really know the answer to either. There are roughly 100-400 billions stars in our galaxy. There are roughly 100-400 billion galaxies in the
observable universe (I believe the estimates may have gone up.) It seems now that a star is more likely have planets or eventually have planets than to not or never have planets. So on the low side a reasonable guess is at least one planet per star which gives us 100 billion x 100 billion which is 10²² planets. If even there is only 1 in a trillion chance of forming a planet like ours, there would be 10 billion planets in the observable universe like ours. I'd wager the odds are better than this. (Note that this discounts the idea of habitable asteroids and moons of large planets.)
Too, it doesn't seem necessary that a planet must in fact be like ours to support life. Perhaps it's not even necessary to support sapient life. So the odds are better yet.
The
Drake equation - Wikipedia is famous for this. It's mostly about finding intelligent life but it is instructive as to why
it's not surprising that we haven't found life, or at least sentient life.
So we've had space flight for ~50 years. We've had a couple missions to the moon where we've found no signs of life. (I believe some non-american, Chinese(?), found something promising in the last year or so). We've had satellites fly by other planets and moons just to take pictures. (Spectrographs, etc., can give us hints but so far we've nothing definitive.) We've had a few probes actually land on Mars. They are capable of analyzing soil samples, but at what rate? A teaspoon at a time?
So the analogy of looking at a shotglass worth of the ocean and declaring that there are no whales is somewhat apt. We've looked at about a shot's glass worth of Mars. We shouldn't be surprised we haven't found life. IIRC, we haven't landed anything on any other moon or planet. So it's premature to suppose there isn't life just because we haven't found it
yet.
Now suppose we do find microbes. Suddenly the idea that life is not rare is not silly. The universe could be absolutely teeming with life, sentient or not. Suddenly, the effort to move our species to someplace habitable or to a place that can be made habitable a bit more than hopeless.
HTH