[FranOntanaya]

I do remember Earth exceptionalism being pervasive, from the first satellite views of Mars up till maybe Galileo's pictures of Europa.

Even today still get that feeling when it comes to the topic of liquid water, where people will point at the lack of meaningful atmospheres and declare places like Mars or any other body holding ices as too different to not be dry, when you just need the right ground temperature gradient and some trapped ice.

[bluGill]

We don't really know what life requires. We know that earth has life. We have insufficient evidence for anyplace else (there is some evidence of life in our solar system but it could have been life that escaped our orbit by chance, or just contaminated sensors). All we have for sure is life exists on earth, so we know life exists on earth.

Wikipedia has a list of other chemistries that could maybe support life, but we don't know if they do in the universe or not. We know that the basics of life on earth (water, carbon) are very common in the universe, and so there is no reason to think that life as we know it should be rare - but we also have no evidence of life elsewhere (mostly because we don't even have the ability to see evidence if it exists - the universe is large and we can't detect the important things even a few light years away)

[mcmoor]

And also that all our sister planets isn't like earth, and they all don't have life (as far as we observed). So it's another point for "not like earth"->"not have planet". Before those expeditions, we thought that fucking sun also has life on it https://adsabs.harvard.edu/full/2011JAHH...14..169C

[GMoromisato]

"Earth exceptionalism" is still the best answer to the Fermi Paradox.

Maybe we're the first/only civilization in the galaxy. If so, then the question is, why? Maybe we're just the first and there will soon be millions of other civilizations.

But most likely, Earth is a fluke. Either something in its environment made it conducive to civilization or some random (and rare) evolutionary path led to civilization.

My uneducated guess is that microbial life is relatively common, but multi-cellular life is very rare and technological life is unique (at least in our galaxy).