There's one thing that totally makes me not doubt there are aliens exist. Carl Sagan's Pale Blue Dot speech.
"We succeeded in taking that picture [from deep space], and, if you look at it, you see a dot. That's here. That's home. That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, thousands of confident religions, ideologies and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every young couple in love, every hopeful child, every mother and father, every inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species, lived there on a mote of dust, suspended in a sunbeam.
The earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that in glory and in triumph they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of the dot on scarcely distinguishable inhabitants of some other corner of the dot. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity -- in all this vastness -- there is no hint that help will come from elsewhere to save us from ourselves. It is up to us. It's been said that astronomy is a humbling, and I might add, a character-building experience. To my mind, there is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly and compassionately with one another and to preserve and cherish that pale blue dot, the only home we've ever known."
And to quote Richard Dawkins...
Are there things about the Universe that will be forever beyond our grasp? Are there things about the Universe that are... ungraspable?
I mean, we are merely a DOT compared to the rest of the universe. Not even a dot. Not even an electron. If the Universe was the Milky Way, Earth would be smaller than an electron.
There are things in the universe, dealing with organic life, that will always be alien. Things we as humans will never be able to truly understand. The Universe is the grandest thing there is. So much variety here, there will be just as much variety between planets. Comparing Earth-life to another planet's life will be like comparing a human to any extremophile bacteria. Totally different.
One planet holds all the variety we know. EVERYTHING we know is limited to Earth.
Imagine how much MORE there is to the universe. Then imagine we're the pinnacle of nature's splendor. IT... It is just ridiculous. The idea there is no alien life is so arrogant.
You can say there's no proof alien are real.
Well, there's more proof they exist than that there isn't. After all, WE exist. We came to exist. Why Earth you might wonder. It could have been any different world. Well, back then it's not as if the universe was setting out to make Earth like it is. It was just following the laws of nature.
I wonder what life could exist in a gas giant. What life could exist on the moons of Saturn and Jupiter, in their oceans underneath the surface. We found water in the solar system. Meaning that water isn't unique to Earth.
In most instances where there is liquid water (Meaning we can't count the moon) there is an enviroment similar to what life here on Earth is used to. Where there is ice water, there is going to normally be traces of a time where liquid water was around. And on Mars there is. We just can't find life there now most likely.
To say there used to be life on Mars is likely. But because it is smaller, it died faster. Appearantly, fast enough that complex life never arose.
If we gave Mars an artificial magnetic field, and heated it up a bit on the surface... I say we'd be able to live there. So I'm sure you'd be able to find life there in the past, as bacteria.
If in our solar system we most likely had past life on not just one planet, but two, and there MIGHT be life on a moon orbitting a gas giant...
The chances of life as we know it aren't that small in that mind set. Not every solar system, but there will most likely be a few.
Life as we don't know it will happen though. There will be things so alien we can barely see them as life at first. But they will be alive. Triple-helix life forms, Silicon-based life forms, maybe even beings so alien no one on Earth has imagined them yet. I mean, who could have imagined some of the things on Earth alone before they were found to exist? Some things on Earth look alien - life from another world will be even MORE alien.
There's an interesting exo-biology program called Snaiad, which is a joint-effort to create a fictional biosphere of alien life. It's very interesting, and the life proposed by it is nothing like Earth life. And there will probably be things even more alien than that I bet.
