Originally Posted by joshuaaaronhodak
Forget about Von Daniken for this discussion. He took it quite a bit too far. But let's discuss the possibility of alien visits regardless of claims by some that aliens were responsible for human achievements. I feel it is very plausible. In the search for extra-solar planets some astronomists contend that there may be more planets than stars in the universe. Having this knowledge there are still so many rational people who are arrogant enough to believe that earth is the only harborer of life. I contend that we will be capable of inter-stellar travel at some point in the future. So, why not some alien race that is potentially much older than ourselves
There is no logical reason to assume that aliens do not exist. We must believe so, because we know that at least one "seemingly intelligent" species has already evolved in this Universe. Which adds probability credence to the great likelihood of many others also having evolved on the trillions of bodies within just our own Galaxy. And some may be far older than us. Especially since the universe is guesstimated to be at least 10 billion years older than our own solar system.
However, what it all comes down to is the number of intelligent species that may have evolved in our Galaxy and the ratio of survivability within this number. If we find life on any other bodies within this solar system, such information will greatly increase the probability for intelligent life elsewhere. If we find many bodies within this solar system with life on them and under such diverse conditions, then we can assume that the Universe is very fecund.
It is not outside of reasonable contention to assume that an intelligent species (which evolved long before us) may have researched and even possibly walked on the bodies of this solar system. Mainly to do just as we are now doing...to investigate and categorize this solar system. Possibly these extra-terrestrials may have noted that life has already begun its evolutionary path here on Earth and potential other bodies in this solar system.
Which begs the question as to why they would spend resources to come here but not remain? Obviously they themselves may never have actually set foot upon Earth, but their investigatory devices might very well have. Moreover, they may send periodic exploration devices to see how everything is going here.
One has to consider the economic and physical realities of exploring every single body in just this galaxy alone. Every human being currently alive has 10-15 solar systems each to explore in this Galaxy of 100 billion stars. Not to mention all the planets, asteroids, dwarf planets and moons each one of these solar systems may contain. You could spend an entire lifetime merely exploring one solar system and never fully exploring it all.
Our solar system is quite far out on one of the spiral arms of the Milky Way Galaxy. Whatever aliens may exists simply have not found the time or wherewithal to explore and colonize this obscure system. Even if they could.