Any one of these things would be a massive boon to our understanding of life throughout the solar system and broader universe, right down even to here on Earth. All three of them would arguably mark a new era in Earth's history.
we are very screwed if they find life on Mars. It means life is incredibly common and thus the Great Filter theory is true and we only have a few years left as a species most likely.
I find it extremely hard to believe you could kill every human being on earth at this point. We’ve reached critical mass, we aren’t going anywhere. When we had that few thousand individuals population bottleneck in the past was when it was dicey. What sort of event could kill every human and end our species? I can only think of planet-wide extinction events like massive asteroid impacts that sterilized the whole earth. And we haven’t ever had one of those in billions of years. Call me too optimistic but I think humans are too resourceful. Some of us would survive anything smaller.
Disagree. If there is a filter at all then it could easily be that we’ve already passed it. Maybe the filter is the formation of multicellular life, for example. Also, Earth and Mars have exchanged a lot of material. If we find Mars life, it would not at all be surprising to learn it is related to Earth life.
Earth is pretty special. We’ve got a big ol’ moon (seriously, the Moon is huge for a planet our size), Jupiter running interference for us with its massive gravity and incomprehensible magnetic field, our host star is very polite, we’ve even got a magnetic field AND ozone layer on the planet itself. Not to mention it’s kept life going for 30% of the age of the universe. It’s a good CV for Great Filter applications.
Some interesting reasons: the proverbial "2nd genesis", panspermia possibilities of our own planet, and answering lots of questions on formation of life on ours and any other planet we might encounter.
