Re the above claims:- Yes, in recent times, a claim of 100 billion planets in our galaxy has been made. However, most of those planets are around red dwarf stars which give off very little heat. To be near enough to get enough heat(ie the habitable zone), they generally end up tidally-locked so that one half of the planet always faces the sun. Currently, only yellow or orange stars are considered remotely likely candidates for producing life-bearing planets. Other stars are too big and thus have too low a life-span.
Obviously, without faster than light travel, no aliens could visit us, so the issue of aliens would be irrelevant in that case. If FTL travel existed, then the prime motivation for exploration, as with humans, would be to colonise other lands(ie planets in this case). Therefore, we humans would get put into reservations, just like before. The only way out would be if one believed in transhumanism, in which case it might be possible that aliens might migrate to other more interesting dimensions as soon as they could, thus not needing to explore their own current dimension.
