In reply to Timmd:
> The converse is also true, that we have no idea exactly how likely it is to happen somewhere else.
That isn't the converse, it's the same thing. Until/unless we know different it's reasonable to assume it's broadly the same everywhere - at least everywhere we can observe, where the laws of physics seem to be the same as they are here.
The only objective position to take on whether there is life elsewhere in the solar system, is to say that we lack the knowledge to discount it, and that it remains a possibility which we have to entertain until we find something to prove otherwise.
That's the point of the 'oracle' thing I posted. Just because there is almost certainly someone out there doesn't mean we are not alone, maybe they are alone too. You can't really prove a negative, like Bertrand Russell's teapot. You can prove there is life out there somewhere, you just have to find some.
To prove something doesn't exist you have to look for it, quantify how hard you're looking and how long for, stir in a few educated guesses and do some statistical analysis to show that if it existed you should have found it for now - the whole process is much less satisfying that discovering something, but perhaps equally important. This might be where we're heading with the search for dark matter, as the big fancy underground dark matter detectors still haven't detected the stuff. With extraterrestrial life we've barely begun turning over a few of the more accessible rocks.
And we need to be careful how we go about looking so as to avoid contaminating or destroying the very thing we're looking for. That Israeli moon mission that dumped a load of tardigrades on the Moon - it would be absolutely unforgivable if something like that were to happen where there is life.
> Even if it's just a few cells bumping around in some goop as it were, it's still life - ultimately.
For what it's worth, I think we might find extraterrestrial microbial life some time soon. But then there are several Drake equation factors along from there before you get to us, and a bit more beyond where we're at to get to the kind of life that might actually make contact with life from around some other star.
That's a possible answer to the Fermi paradox right there - is it inevitable that we will destroy our civilisation and ourselves before we get off this one planet and start to explore the galaxy? It's a possibility, certainly. Just now it seems more possible every day.