If Alien is real, do you eager to see Aliens?
Most Helpful Guy
Short answer: Yes
Long answer: Probably. When most people talk about aliens, they mean intelligent aliens. When I say there are probably aliens, I'm referring to any life that's not from the earth. There are about 300 billion stars in this galaxy alone, and there are about 400 billion galaxies in the observable universe. That's A LOT of stars! The recent Kepler mission tends to lend credibility to the idea that planets are not the exception, but the norm. With all those planets, there's almost certainly SOME that are in the Goldilocks (not too hot, not too cold) orbits around their parent stars. Now life on the earth happened fairly quickly (roughly 500 million to 1 billion years after its formation... which geologically speaking is fast). This suggests to many scientists that if life can happen, it WILL happen. But as easy as it is to make amino acids, it's just as easy if not easier to destroy them. So the number of planets where life actually happens may very well be rare. As for intelligent life, more than 99% of the history of life on Earth didn't have intelligent life. About 75% of the history of life on Earth didn't even have life you could see without a microscope. As for life with technology, about 80% of human history was spent with spears and animal skins being "high tech." So as for life on Earth, something like 99.999something% didn't have any high tech, intelligent life on it. This suggests that intelligent life may very well be rare in the universe (indeed, even animal or plant life might be very rare).
However, here's something to consider. For every single blade of grass on Earth, there are about 10,000 class G main sequence stars (like our sun) in the observable universe (to say nothing of the other classes of stars). Although the odds of any one planet having intelligent life are fantastically slim, there are a fantastically large number of pulls on the alien life slot machine.0