MtPollux t1_j85uau5 wrote on February 11, 2023 at 9:23 PM

Scientists search for planets with conditions similar to earth because they know those conditions will support life. This doesn't rule out the possibility that other life forms could exist under other conditions, we just haven't discovered other types of life forms so we don't know where else to look or what else to look for.

dastardly740 t1_j865uj3 wrote on February 11, 2023 at 10:49 PM

Also, for exo-planets, in particular, we have a decent idea of what to look for for earth-like life. Claiming some other observation is a sign of non-earth-like life is a much more difficult conclusion to make.