I think that aliens could be real otherwise germs would have no purpose other than to kill on the planet Earth. Their only use could be to ward off alien attack.
They are about as usefull as the human race, and are trying to survive as well.
As for the actual topic: Aliens, yes they MUST be real, I mean, there are what? Billions upon billions of planets and solar systems, and through math, the possibilities of E.T life is extremely plausible. Even one of the theories is that we are started from E.T life, bacteria which hitched a ride on a ice comet which plummeted to Primitive Earth.
They would be something that is very likely: 1. Without cells. 2. Very diffrent organs 3. Sientists would be very unsure about wether it is really alive. 4.Without DNA
Real in the sense of another life form than humans. Wither that be simple bacteria, or advanced life forms such as ourselves. But I do not think there are green martians running around in saucer shaped disks defying the laws of physics.
The universe is divided into superclusters, which are divided into millions of clusters, which are divided into billions of galaxies, which are divided into millions of solar systems like our own. The chances of Earth being the only life in the entire universe is so small its almost funny.
It would be absurd to assume that we are the only planet in the entire universe that developed life. I believe that chances are with a billion other planets, even if the chance for life developing on a planet is 1 in a billion, that still makes it PROBABLE for there to be life elsewhere. Now how close that is and whether or not it is sentient and whether or not it is just beginning or ending or something, that's a whole different story. I beleive that there are other life forms out there, it just may be that we never meet them because the universe is so big that we can't even imagine how big it could possibly be when imagined.
I think that there could be aliens that have found us but we haven't found them but I agree with Binary that there's no little green people floatin in magic saucers flyin in the air and liftin cars with their minds
