Mankind is infantile. On a cosmic scale, we are tadpoles. We have no ability to understand OURSELVES, much less the finite, infinite, and deepest inner workings of the galactic and universal stage. What we call atoms, something out there most likely calls flatulence.
We have no way to verify it. We have no way to disprove it. Thus, it cannot be wholly denied or proven by our infantile sciences. Yes, out "infantile" sciences. Just because we can explain something in life to our own comfort zone, means little to the infinite cosmos. It's a blanket we alone wear.
Thus, I choose to ASSUME, yes, that life exists outside our "man dominated, one sided delusion of dominion".
The mere fact that animals known to our science exist that can live in vacuum proves that life can and does get around. We are simply too short lived, and too technologically inferior to our own delusion, to be able, as a race, to accept we just don't know, and most likely will not, for eons to come.
The Drake Equation actually proves that ET is highly possible and common in the universe. Theoretical physicists Michio Kaku argues that ET can be possible. We don't see ET because we only scanned 100 light years away from Earth. Consider his lamp post analogy. When someone lost his key, he stands near a lamp post to look for it. However, a nearby person would say, "why did you stand there, when your key is dropped right here?" The guy near the lamp post would say, "well, because there's no light over there, so I will look over here." It's the same thing as looking for ET: we have to use a source to look for something. However, our technology is too primitive. In SETI, we can only detect the frequency of hydrogen in the galaxy for incoming messages. Kaku said that most highly advanced civilizations can send messages from all frequencies so a passing star will not interrupt the entire message. This means that if we ever received their messages, and since we can only detect the hydrogen frequency, we would read nonsense or gibberish. Thus, we can be in the middle of a intergalactic conversation and we might not even know. Ancient astronauts and UFOs could be from highly advanced civilizations. He says the reason why we think ETs don't reach us is that we assume their technology is only 100 more advanced than us. True. Yet, we don't assume ETs are Type 3 civilizations (millions of years more advanced than us). "That's a mistake," says Michio Kaku. It is possible that type 3 civilizations existed in far corners of the universe and visited us before.
Consider the Fermi Paradox, which criticizes the Drake Equation: if extraterrestrial civilizations are common in the universe, where are they? Where is everybody? Surely if any highly advanced civilization is out there, they can easily reach us by using hyperspace travel and detecting our signals.
Michio Kaku replies to the Fermi Paradox, saying Type 3s don't come here because we simply aren't interesting to them. He argues that we cannot be arrogant in that we assume they must come here and give us some of their super technology. Right, they will ignore and drop all their important businesses just to come here and give us some of their trinkets. That's just silly to believe. For example, consider the ant hill and the city. The comparison between a type 3 and a type 0 civilization is the same as the comparison between an urban city and an ant hill. First of all, the ant will obviously don't know what a city is, just as we don't know what the UFOs are. Second of all, when a man sees an ant, will he say to the ant, "take my to your leader, as I will grant you guys with super technology and knowledge: I will bring you beans, I will bring you stellar energy, DNA technology, and immortality"? No, he will simply crush on a few of them, or at least ignore them and continue with his own business. Aliens may have visited us before, but never bothered to return because we're simply not interesting to them.
Personally, I believe there are probably plenty of type 0 civilizations and maybe one or two type 3 civilizations across the universe. Most ETs don't reach us simply because their technology is just as primitive as or lower than us (not being able to go faster than the speed of light or ripping space-time for hyperspace-travel, for example). Therefore, the fact that we don't see ETs is simply because many ETs out there are probably less advanced than us and couldn't get to us with their primitive technology. Maybe they have only survived their first ice age. I think this is a better argument, as it could argue why we don't see ETs out there and why ETs exist in the universe.