Extraterrestrial life is defined as life that does not originate from Earth. It is unknown whether any such life exists or ever existed in the past, although many scientists think it likely that on Mars, for instance, life either exists or has existed.[1] Various claims have been made for evidence of extraterrestrial life, such as those listed in a 2006 New Scientist article, which the magazine describes as "hints" rather than proof.[2] A less direct argument for the existence of extraterrestrial life relies on the vast size of the observable universe. According to this argument, endorsed by Carl Sagan and Stephen Hawking, it would be improbable for life not to exist somewhere other than Earth.
The development and testing of theories about extraterrestrial life is known as astrobiology, exobiology, or xenobiology. One possibility is that life has emerged independently at many places throughout the universe. Another possibility is panspermia or exogenesis, in which life would have spread between habitable planets. These two hypotheses are not necessarily mutually exclusive. Possible forms of extraterrestrial life range from simple bacteria-like organisms to sapient beings far more advanced than humans.
Suggested locations on which life might have developed, or which might continue to host life today, include the planets Venus[3] and Mars; moons of Jupiter and Saturn such as Europa,[4] Enceladus and Titan; and extrasolar planets such as Gliese 581 c and d, recently discovered to be near Earth mass and apparently located in their star's habitable zone, with the potential to have liquid water.[5]
Beliefs that some unidentified flying objects are of extraterrestrial origin (see extraterrestrial hypothesis), along with claims of alien abduction, are considered spurious by most scientists. Most UFO sightings are explained either as sightings of Earth-based aircraft or known astronomical objects, or as hoaxes. Some sightings have remained unexplained, in some cases having been reported by trained professionals.






Close Encounters: Proof Of Alien Contact
Featuring purported proof of alien existence in the form of interviews with government scientists and astronaut Gordon Cooper Watch Now ›

 

There's no way that we're the only "people" around.

 

I agree- with all the tons of stars and planet systems out there; I'm sure there has to be at least one other planet that can sustain life, even if it is just simple plants, bugs, etc.

Now I don't believe that they look like the typical humanoid- green alien; nor that they fly around earth's desert areas in little disc shaped ships like all kinds of movies and such have made so famous. But I do believe there has to be some kind of life out there.

 

I believe so.

 

I used to believe there were other life forms out there. But I don't think there are any life forms advanced enough to have mastered space travel like Star Trek shows us. (We haven't mastered space travel yet either. We can barely make a manned journey to the moon and back.)

I have to think if there was a life form that was advanced enough to have UFO spaceships travelling great distances with advanced propulsion systems. They would've recognized our planet as something to conquer, and used us as primative servants by now.

 

There are billions of stars in our galaxy so, I'm guessing, at least one of them must a have life carrying planet. Now, I don't know about UFOs. If there are any alien civilizations capable of traveling the immense distances between solar systems, I haven't seen one yet.

 

There has to be somthing else right?? I mean, who else could have come up with the idea for "slim jims"??

 

my citys full of em!......(people)

 

there has to be something else out there! we can't be the only ones!

 

There is certainly life out there is space. The universe is so huge the even the rarest occurrences (like the evolution of life) have to happen more than once. However, I find it improbable that they have been studying us covertly of decades and have a disturbing fascination with our a$$holes (i.e. the reported probing).

I'd say most of the "sightings" to date can pretty safely be written to other explanations.