Well there is obviously no conclusive proof that aliens exist. However, the probability they do is far closer to one than it is to zero. Just by the pure vastness of the Universe.

Imagine shuffling a deck of cards and then drawing directly from the top the four aces, the chances are slim - practically zero. But now imagine a near infinite number of decks all doing the same thing - one of those is going to give the result we're looking for.

Alas, the sad truth is we will probably never actually encounter alien life. The nearest planet that scientists believe could withstand such life is millions, if not billions of light-years away.

That is to say, a planet not too unlike Earth which has it's own heat and water source.

Having said that, I wouldn't be surprised if we discovered very primitive signs of life on Mars or Titan - cells and such. Or evidence that such things once existed there.

So to recap: a very slim chance that we encounter any intelligent lifeforms (unless they have the technology to reach us), a even slimmer chance that we discover unintelligent lifeforms but a slim chance we discover signs that primitive life has or does exist.

I hope that clears it up for you.

More (off topic) rambling:

We should be more excited at the prospect of creating our own life - as you've seen recently, scientists have made artificial life - the possibilities of such technology are endless. From creating new limbs for amputees to abolishing world hunger.

Mapping the human genome is obviously a huge leap forward too. By discovering what 'DNA' button controls what, we can start to eliminate the likelihood of cancers and other ailments.

In the distant future the human race may have to modify it's DNA to cope with global warming, making us more agreeable for a warmer climate. Or perhaps to decrease the metabolism of soldiers - meaning they could survive for weeks or months with little need for food or water out in the battlefield etc.

The odds of drawing 4 aces from muiltable decks of cards does not mean to suggest that such things exist! Nor in any other context for that matter.
I like the use of font colors to break down the paragrath tho Rob. It makes it alot easier to undertand.
Besides, I heard people used to believe in Dragons... Ive never seen one, have u? Maybe there are fossils of one buried in some desilate mountain somewhere.
This is a good time to bring out the old jack of spades dont u think?

Awesome man, I never imagined this thread would lead to a film recommendation - I'll check it out, thanks.

Ur really not helping ur cause here.
Nor is saying that there is no proof, obviously!?