Actually, most planets are detected indirectly, by the influence of the planet's gravity on the parent star. Only a few were seen by direct observation, not by reflected light of it's parent sun, but by the light of the parent sun that the planet blocked as it passes in front of it's parent sun.
Btw, I think you overestimate our self destructive potentials. Even all out nuclear war or the worst imaginable environmental catastrophe will not exterminate homo sapiens, but would instead leave enough survivors to mount another try. Even if we are literally reduced to the stone age without even recollection of our previous mastery of natural sciences and technology, it seems likely that it would take but 10,000 years or so for us to be building nuclear weapons again.
Btw, I think you overestimate our self destructive potentials. Even all out nuclear war or the worst imaginable environmental catastrophe will not exterminate homo sapiens, but would instead leave enough survivors to mount another try. Even if we are literally reduced to the stone age without even recollection of our previous mastery of natural sciences and technology, it seems likely that it would take but 10,000 years or so for us to be building nuclear weapons again.
