Plain and Simple. What would be the impact on our existence if we found intelligent life on another Planet?
Maybe humankind would get humbled in the fact that we're not the only sentient beings in the universe. Or we may get too excited over the fact that we're not the only sentient beings in the universe. Provided, of course, that there is intelligent life on another planet. =)
we earthlings would probably go to that planet and destroy that one too.
Fear and panic. It is most likely be that humans would view life as a threat and find someway to enter into a war.
A less intelligent species could be exploited and enslaved. An intelligent species would be a rival and threat.
"We come in peace," is something of science fiction when it comes to humans.
same things humans made on earth, arts, commerce, architecture, education.
Either the European-Native American thing will happen or it will be like my country's culture relationship with the rest of the world.