Dwaino is there any subject you know nothing about?.....your knowledge is quite frightening.
Ok here goes .can you tell me whether UFOs exist?
UFOs could be anything. Unless you're talking about extra-terrestrials. I believe they could be quite likely. Stars form in nurseries along with other stars. Therefore a star and it's system of satellites would/should roughly consist of a similar composition as its neighbours. Our sun was born in one of these nurseries about 4 and a half billion years ago and many of our closer neighbours were formed from the same materials of our sun. This means that many of the closest solar systems have very similar make ups to our own too. Complex organic proteins and amino acids are in abundance and found everywhere, from moons to comets. What if a neighbour developed intelligent life at the same time dinosaurs dominated ours? Think of our scientific advances of the past 70 years, and imagine if we never had a dark age for nearly a millennia, how far would science be? A civilisation only 1000years ahead or even 65 million years ahead could find their way here. Even if faster than light or 'worm hole' travel were not possible, the likelyhood that they would already be in our neighbourhood is very high. From the time the first extra-solar planet was discovered, more than 2000 more were discovered in the next few years. We are now discovering systems like Gleise 581. Imagine the kinds of systems we would be able to discover in 10, 25... 50 years? Using Gleise 581 system as an example, an intelligent civilisation using the same methods we use would be able to detect activity here and now. We're only 22 light years away. Now imagine things like the Doppler effect and how space-time warps in the presence of gravity. Maybe space-time can be compressed ahead and expanded behind, like how the Doppler effect explains short and long light (and sound) waves. All of the sudden the distance becomes less. We were originally told life is fragile, and biospheres are believed to be uniform in their composition. We have recently discovered arsenic based life forms on Earth, as opposed to our own water based. Some argue now that we are not even related to these weird specifies but are in fact extraterrestrial and arrived here on comets or asteroids.. Like how some believe we arrived here originally (see: panspermia). Either way, it proves life can take on some strange forms and not always as we know it (go look up some extremophies or chemotrophs).
Edit: excuse the formatting. On my phone