I'm pretty sure there are lots of Earth-like planets in this universe. There are of course many details that all have to be taken into account when determining if a planet could be suitable for life in the form we know it, but considering that our galaxy has got 300 billion stars and the observable universe (which is just a part of the whole universe) contain over 100 billion galaxies, I'd say the chance there's no other star that has got even one earth-like planet is close to zero.
As far as any other earth-like planet being inhabited by some kind of life form, it's a bit harder to calculate the probability. We know about one earth-like planet (the Earth), and that one contains life, so that would make the probability of an earth-like planet containing life 100%. Then again if it didn't, we wouldn't know about it because we wouldn't exist, so that calculation goes out of the window... But if I'm going to make a wild guess I say I definitely think there is life on other planets.
Are there intelligent life forms on those planets? The Earth has had several mass extinction events where most of the world's species died out, and there's no evidence that any of the earlier geological eras produced any intelligent species before they were wiped out. I would assume that even if there are lots of inhabited planets in the universe, the vast majority of them would only contain micro organisms at any given time. Then again, I think it would be weird to assume that the number of planets with intelligent life would be exactly one. So my guess is a large number of inhabited planets, of which only a very small percentage has intelligent life forms.
Do I think any humans will ever meet an alien life form? Definitely not. Even if it would be physically possible with the right technology for fragile intelligent life forms to travel the type of distances that we are talking about (which of course nobody has a clue about at this point, but which i seriously doubt), I can't see how any given life form would have time to figure that out and then actually do it before it goes extinct.
I also think it's difficult for anyone to appreciate the distances we are dealing with here, since they are so far beyond the capability of our imagination. This website is pretty interesting although it didn't do much more for me than help me realize that my brain can't imagine sizes and distances that aren't extremely close to my own size: http://scaleofuniverse.com/
Well put. Our first step is colonizing Mars which will happen by 2032. It'll be a one way ticket. Followed by building bases on the moon. The gases of the solar wind could be useful for future lunar bases, since oxygen, hydrogen (water), carbon and nitrogen are not only essential to sustain life, but are also potentially very useful in the production of fuel. There's also titanium (Ti) material to construct ships.
*NOTE* Saturn's moons have more oil than Earth.
Perhaps our species would have to put all their technology in a time capsule for the future generations or species to pick up on.
So far everything we have imagined has come to life.
Candles to light bulbs.
Telephone to cell phones.
From automobiles, trains, planes, and eventually landing man on the moon.
All this in a very short life span relative to the existence of Earth which is 4.54 billion years old.
I say it can be done, but it would take the intellects of every country working together. The most successful species in terms of length of existence and biomass are not humans, but ants. They work together as a single cohesive unit. I believe that's our cue along with focusing all resources and man power on research and development for space exploration like what Elon Musk is doing.
Keep the discussion going. Some fascinating stuff here...
Marcus Aurelius: Tell me again, Maximus, why are we here?
Maximus: For the glory of the Empire, sire.
Baked, not fried... the healthy choice.