Scientists and novelists have long dreamed of extraterrestrial life. Thanks to NASA scientist Richard Hoover, we now have good evidence that there is such a thing.
See the story in Reuters and looked up the Journal of Cosmology is you're a die-hard: http://www.reuters.com/article/2011/03/06/meteorites-life-idUSN0627219120110306
Summing it up, Hoover examined meteorites and found fossils of bacteria that almost certainly aren't found on earth. I know this isn't exciting as ET flying a bicycle over the moon. Yet, it proves a point that could lead to greater possibilities. Earth isn't the only place that has life.
How advanced is extraterrestrial life? Should we be afraid of it? Those are themes you'll see explored in my novels, including The Centauri Generation and Mute. Samples available on www.authonomy.com.
There's a big difference between the aliens dreamed up by writers and what Hoover found. Bacteria is very resilient. It can live in acid, in Arctic ice, in sulfur deposits and in frozen soil. In fact, the bacteria that Hoover discovered were on meteorites that likely came from a comet. Seriously, comets are flying around with microscopic aliens hitching a ride. Think about that next time you see one streaking through the sky.
Bacteria is resilient, but animals are not. They are slower to adapt to extreme climate conditions, which can be found on many planets. Because they are larger, it's harder to live sheltered from the radiation in space. Animals need stable conditions to survive. We know there are millions upon millions of planets and moons out there, but it's hard to say which ones have conditions that would support not just life, but large, complex organisms.
As for intelligent life, it's an even bigger mystery why that forms. I say it's in God's hands. That's the only way I can explain why so many things about Earth are perfect for humans, like it was designed for us.
Evidence of extraterrestrial beings is a message. Life has few limitations. If life can exist on a comet looping from deep space to the sun, why can't we recognize how fortunate we are and make this big rock a more pleasurable ride?