We need to find analogs to our Sol system - you know, tiny rocky
planets near the star and big gassy ones farther out, and finally small
icy ones that the natives can debate about for years as to whether
they are actual planets or not.
Most solar systems we have found so far look nothing like ours.
Hopefully this is due to the fact that we can so far only detect really
big worlds very near their suns.
Since we know giant planets exist, we should also be looking for any
moons around those worlds which might have life, such as Jupiter's
Galilean satellites. Those powerful telescopes planned down the road
that can directly image exoplanets should be able to do the trick here.
And of course some of those alien Jovians might have life themselves
floating in their extensive atmospheres. We should consider all the
possibilities so we don't get caught up short again by being too
conservative.
Space/Science » in reply to It would mean we don't understand solar system formation
More than just finding another Earth