Once on this fascinating show called "How the States Got their Shapes" they showed this chart demonstrating how, within a pretty impressive margin of error, those areas in the U.S. which have the highest numbers of reported UFO sightings are clustered around the locations of the sorts of military bases where top secret aircrafts are developed. I haven't bothered to check the figures and there must be a tremendous amount of unreported sightings as well but if the chart is true then it looks too close to very easily be a coincidence. It would also explain not only what most of these people saw but also why the government is so adamant about denying everything and even why in some cases they might possibly go out of their way to cover it all up.

Of course none of that proves anything, and even if nobody's been visiting us that still doesn't mean that nobody's out there. From the way some people talk you would think insterstellar travel were literally impossible but all it would take is a species of equal cognition (NOT greater; have humans gotten smarter in the millenium or so we've been advancing technologically?), a body built for constructing technology, a long enough civilization to have developed it quite far, and either a long-lived species or one with a degree of technological sophistication capable of making ships which can sustain more than one successive generation. On the other side of the coin you have equally silly arguments from believers based on some infinite monkeys principle, which as far as I can tell is just a form of the appeal to probability fallacy. I myself don't really have an opinion on the subject at all, or not right now. All I can definitely say is that these close encounters stories are bunk since they always involve extremely humanoid aliens, the odds of which are absurdly low. Nobody ever reports seeing an alien that actually looks *alien*.

I think alien do exist because look at Stonehenge or the other stuff we humans create before advance technology came. How human suppose to move thousand of pound rocks.

Considering how many stars there are, aliens NOT existing would be almost impossible.  Around any given star, there is a habitable zone, in which life could arise. Aliens have probably not been paying us visits, but somewhere out there, they probably do exist. The intelligent ones could be debating the same question right this minute. 

I am sure that aliens do not exist in our galaxy. But maybe in other galaxies. But this is only my opinion.

As many others have said before me, the chances that there is some sort of alien life are extraordinarily large. However, it is most likely not how the society traditionally believes about aliens. Most likely, the most common "alien" would be some sort of bacteria that exists somewhere other than Earth. It is already proven possible for bacteria to exist in arsenic other than the usual phosphorus. If species can exist in arsenic, why not other places? Then there is the fact that the sheer number of galaxies in our universe, and the high probability of Earth-like planets in at least one of those trillions of galaxies, point towards the possibility that there are alien species living somewhere out there. The thing is that it is also extraordinarily unlikely that we would be able to come into contact with them or vice versa. The distances separating us from most of the universe is unfathomable right now. Aliens would have to a.) know where we are b.) have the technology to reach us-period, and c.)be willing to spend hundreds, thousands, millions, billions, pft trillions of years- millions or billions of human generations (you never know- the lifespan of an alien might be different, but the idea is the same) to reach us. It just wouldn't be practical. Aliens=yes. Abductions and all that nonsense=no.

When I was younger I use to believe that aliens actually exist. Now that I'm older and that I never seen them I don't believe in aliens anymore. But who knows ? Maybe there are aliens out there within the solar system.

I have yet to be given solid proof as to the existence of aliens. However, it is a possibility that they exist. Who says they have to be within our solar system? There could be another planet far from here where aliens are just living iut their daily lives.

Well.......I am of the thought process of  with sooooooooo many galaxies, solar systems, and universes it would be kinda dumb not to think there is some aliens or life out there.

Well of course aliens exist,do you really think where the only life forms in the whole universe?

With the abundance of Carbon, Hydrogen and other life-creating elements that exist in the universe I really don't see how people wouldn't think there are other life forms that exist.

Aliens are real , they are just afraid of humans . They visit earth for water , their original home / place was on mars , mars is one of the very dry planets on the solar system .. Aliens need water too ..

I sortha kinda think they exist but than something then tells me that they don't exist because wouldn't they be down here already with their little space ships.

I'm positive alien life does indeed exist, however its likely not akin to that of Science Fiction. Most alien life forms are likely the size of bacteria or, at most, a small rat. Though I'm not opposed to the idea that an intelligent life could be out there, I just don't think it would ever come into contact with us, and if such a life form existed its likely about as advanced as our culture, depending on what material their planet may have and what scientific advancements they may have made. Then again space is huge, and there is so much unexplored pockets of space. For all we know a Cthulhu-like entity could be roaming the infinite void, right?

I do believe that some kind of alien life form do exist somewhere, probably some form of bacteria or something,
but we probably never see them or them us.

the size of the galaxy makes that a hige probability in my eyes, that there must be one planet that can support some kind of life, but probably so far away we will never know about them

Regard
Blucoll

What are the chances that Earth is the only planet in the entire universe that has intelligent life? We are such a small portion of the universe that we have pretty much significance in the grand scheme of things... we barely know the contents of our own solar system... and not perfectly... why is there so much universe outside of what we know if it's just completely devoid of life? It doesn't really make any sense if you ask me.

I can honestly say that i don't think aliens exist because if aliens exist i know they will have they little laser guns. and if they have they little laser guns than they will been tried to evade earth. Thats just pure common sense.