I could go on but I don't really see the point. We have the drake equasion. And the variables differ so greatly the results range from 0 to millions.
Forget about the Drake equation. The Drake equation works from the little picture up. Think of it from the big picture and work backwards this way,…
There are only a handful of natural elements in the universe (under 200 of them). It appears that they are distributed pretty much in the same proportions throughout the observable universe. So we can think of the universe as a huge crock pot that contains the ideal ingredients in the correct proportions for the recipe of life.
Astronomers currently believe that there are approximately 70 thousand million million million stars in the observable universe. (that represents the number of chances for life to evolved because we at least need a star for this to occur)
Now, just for kicks let's suppose that life has a one-in-a-million chance of evolving near some star. That would be the same as saying that the Drake equation turns out to be 1-in-million. That would mean that there are 70 thousand million million stars that are supporting some form of life. In other words 1-star in a million gives birth to life.
Ok, don't like that figure. How about we say that the chance for life to evolved on a star is not 1-in-million, not 1-in-10 million, not 1-in-a-100 million, not 1-in-a-thousand million, not 1-in-ten-thousand million, and not even one in a hundred-thousand million.
Let's assume that life only evolves with a chance of one-in-a-milllion-milllion. That's really a very slim chance considering that there are only 200 different elements and they appear to be in pretty much the same proportions throughout the crock pot.
Yet, that would mean that there would still be 70 thousand million stars supporting life.
Or maybe you would like to be a real skeptic and say that life only evolves once-in-a-million-million-million chances. Personally I think that's absurd considering the conditions of the soup in the crock pot. But even if you go to that extreme you still would have 70 thousand stars supporting life.
I personally believe that life has a lot better chance than even one-in-a-million-million chance which would yield the 70 thousand million stars (or more) supporting life as I said previously. I believe that this is a more realistic figure based on the conditions of the soup. The ingredients are just too perfectly proportioned for the recipe. It's almost as if the soup was put together for the purpose of cooking up life.
Life in the universe just isn't all that rare in the big picture, I don't think.