UFO's and Aliens might exist, however Margaret, a man in the LEP and some UFO Sighting forum, is pretty hard to believe.
I do think that we are not alone in the universe. But how do others know we are here?
Search for Extra-Terrestrial Intelligence (
SETI),
SETI Institute - SETI Institute Homepage, have sent a signal into space, but it will take 21,000 light years to reach it's target, and thats on the edge of the Milky Way, our Galaxy. Which is only one of Millions of Galaxy's in the observable universe.
Radio Waves travel at light speed which is 5,878,630,000,000 Miles (Approx) per year.
So we have some deep space probes, Pioneer 10 is the furthest traveled probe, launched in 1973 and is on a trajectory to leave the solar system.
So assuming that alien intelligence had the ability to travel many light years at once, the universe is estimated at least 93 billion light years across, we could have visitors. But as I said how do they know how to find us?
One last point, if there are superior beings out there, looking at us, they could have made contact, if nt why not. If the technology exists to travel interstellar distances, then they would have no problem in solving our language and even could disarm our weapons making it almost impossible for us to hurt them, when they visit us.
So as I said, very unlikely.
