I believe from Nasa studies that space travel for living beings is severely limited because of radiation. There are other planets and most likely other beings on other planets but travelling just five light years is a problem. Aliens seem to abound and everyone has seen one, yet nobody can catch one... even when they crash. Knowing how snoopy the media is, if they existed these guys would produce one or proof of one surely...
John, Kansas, USA

If you want to put unsubstantiated rubbish like this on your otherwise wonderful web site, do a service to the Science section by removing it, and then put the article in a section labelled "Pseudo-science", because that's what it is. Subjects such as this that rely so very little on facts ought not to be put on a world-wide news site.
Matthew, UK

My wife thinks I'm nuts, but I firmly believe that there is an answer out there. It seems inconceivable that within this universe we are the only sentient life form; it also strikes me as being an enormous waste of space, and, as we all know, Mother Nature hates waste. I hope they come back in my lifetime; I just hope we don't mess up the contact.
Doug Craig, Virginia, USA

I believe in Time Travel. Therefore I believe these aliens as we call them come from our future, and they are visiting their past, our time. The earth as we know it does not exist.
Charles D. Immekus, USA

The conspiracy theorists point to things like the US government's determination and ruthlessness in covering up the 1947 crash. Why else, argue the UFOlogists, would the US government engage in such systematic abuse of citizens? Many find it easier to believe in alien visitations than the reality that our government and its high officials have learned to lie regularly about all sorts of things as a matter of course. For various reasons, they are perhaps less frightened by the former than the latter.
Mark Lause, Ohio, USA

The Roswell mystery is, in fact, true. I was there when Nessie shot it down. Best wishes to all who need something to hang their hats on.
Clive Elsbury, S Wales.

It is so obvious there has been a cover up why not admit it for the good of the world
Stuart, Brisbane, Australia

I have worked with military students from many countries, teaching English as a foreign or second language for more than 30 years and have sometimes asked them their opinions regarding UFOs. Around 1972 I taught all the military officers assigned directly to Colombian president Pastrana Borrero (father of the present president) in La Casa Militar in the presidential palace in Bogota. On one occasion I could not resist asking them if they thought the most likely explanation for the more reliable UFO reports was that we are being observed by extraterrestrials. I was fascinated when they all answered in the affirmative. Several years later after returning to the US, I asked a colonel in the Colombian Air Force if he had ever been given a briefing in which he had been told we are being observed by extraterrestrials, and he answered in the affirmative. (This sort of briefing seems to have only been given to those at the highest level in their military) Such responses from seemingly credible, reliable military personnel over the years, for me, tends to reinforce the belief that there most likely was a crash of an extraterrestrial craft near Roswell in 1947.
Cliff Gieseke, Texas, USA

If you've ever driven through Roswell, New Mexico, you'd have been better off driving around. Main Street is about five miles long and about a block deep on either side. Much like the town, the people who live there are long and narrow and not very deep. If you've ever driven through Roswell, you would know why they invented aliens.
Roy B. Conant, USA

In my view, it's simply pointless to give credence to any UFO conspiracy theories, because one can never conceive of a method to falsify them, even in principle. It's much more likely that what the Air Force says happened - did in fact happen. The "memories" of surviving "witnesses" are compressed from other, unrelated events early in their lives. However, I do believe that life is common in the universe where the environmental conditions are right for it. Of course, as here on Earth, the arising of INTELLIGENCE is a much more questionable prospect...
Rob Shaw, Oklahoma, USA.

I believe the first account of the Roswell incident to be accurate. I believe the weather balloon story was a hoax. It would appear that there was just enough initial public notice based on what really happened to forever make it impossible to still the questions about the event. To me later stories by key area residents and, in particular, the military officer first on the scene that conflicted with the secondary Air Force "weather balloon" story were very convincing. As in many cases of unexplained sightings or happenings we as individuals must attempt to assess the quality, reliability, and character of the witnesses. To my knowledge those coming forward had no history of seeking publicity and in fact for many years faced censure if they had come forward. I find that a powerful endorsement for their reliability as witnesses.
John Cooper, Oregon, USA

I wonder why such 'strange' incidents and sightings take place in USA alone. Were there any sightings made in any other part of the globe?
FJKumar

Whatever happened at Roswell, there is no material evidence that it was to do with aliens. While I wouldn't like to theorise too heavily, there are a number of interpretations of the evidence on hand that do not link up to aliens. On the other hand, its certain that it wasn't just a weather balloon that crashed at Roswell.
James Edward Brown, UK

It sounds as if the X-Files is a bit too close to some people's fantasies. I don't believe the story. Almost everyone you see interviewed could have some publicity or financial reason for inventing/perpetuating the story. The story of Roswell is dead. Alien autopsy?? Any kid with a few simple tools and items of plastic could generate such an unconvincing tape. I'm sorry, it doesn't wash. Knowing the government, I don't believe such a secret could be sustained.
Andrew V. Roberts, Colorado, USA

Why America? It seems that all unexplainable phenomena have some connection with the United States. Small towns and deserted highways, yet never in a major city centre. There are stories of other Roswells that have been covered up. If aliens make mistakes with their crafts and occasionally crash into our planet, is it not conceivable that only once they would manage to do it in the middle of the day on a crowded interstate? Of course not. If that happened the mystery would be over and the United States Government would have no secrets such as these. All stories relating to aliens and other such fascinatingly unexplainable topics will remain nothing but entertaining campfire stories until a squadron of flying-saucers crashes into Big Ben just as the clock strikes twelve noon. Let's see if the US can cover that one up.
A.I., Vancouver, Canada

It beggars belief that one of the great news organisations of the western world, a paragon of disinterested journalism and public service, should descend to retailing this sort of arrant and juvenile nonsense. Shame on you. Get back to covering the news, this instant.
Oliver Kamm

I've tried to do some homework on the allegations made by both sides in the Roswell incident. It seems like neither side is convincing. Those who say there was a UFO crash claim there is evidence, then fail to present it. Those who claim it was just a weather balloon sound too much like they merely discount their opponents' claims, again without presenting solid evidence. This is not the sort of debate that leads to the truth, whatever it is.
David Benfell, San Francisco, USA

For some reason, the US government keeps the Roswell matter alive. Every few years, they come out with another "Here's what really happened", each of which does not quite explain all the facts. My belief is that The Roswell Incident is in fact a decoy to distract attention from what is really happening. Probably something dodgy/immoral /unethical/illegal etc.
Jonathon Ward, UK

Now more than ever the public's fascination with UFO's, the unexplained and other phenomena is rife, like an epidemic. Programmes such as the X-Files are more than partly responsible for the current interest and while many people pass it off as harmless fun, it does seem to indicate a general decline in the intelligence of the population. When there are more fabulous and bizarre hypotheses in modern physics than can ever be conjured with in an episode of X-Files, it seems strange for the public to romanticise with what is ostensibly the 20th century's cultural equivalent of witchcraft.
Greg Turner, UK

I find it very telling that even with so many people so keen to prove that this and other incidents have an alien involvement, there has been absolutely no credible physical evidence We've seen time and time again how poor government agencies are at cover ups. I think that is a good indication that there probably hasn't been one here - I suspect that not even Kenneth Starr could make a case for Roswell.
Mark Hughes, UK

I sincerely believe that Roswell really happened. There are aliens who crashed to the site, and the government is hiding it from the world due to fear. But this is not really the matter of the story behind aliens and those kind of stuff. I believe that something deeper is still going on in our relations with them. There are some factions of human beings who are actually in cahoots with them.
Anthonio Catubay, Philippines

If "they" can get here, they are obviously very clever. Why then have we not established proper contact with them through all the efforts which are underway around the world? Surely the most likely explanation is that there was a serious accident involving a secret plane or weapon, and the US Government simply did not want anyone to know.
Dave Kelly, Azerbaijan

Yeah I believe 100% that something very suspicious crashed in Roswell. All the evidence is not conclusive with the US government's "official" statements.. IF aliens/UFO's are hoaxes, then how come so many people believe in them and swear they have seen them?
Abigail Cooles, West Indies

My wife's father was a colonel in the 509th bomber group at Roswell after WWII. There was not only a press release about the alien UFO issued by the Air Force, there was an alien craft recovered. Government lies will not change the facts.
John Wurts, USA

Now, isn't it amazing how many of the UFO "landings"/sightings are concentrated in the USA? Even though it's only a fraction of the total earth's area? And isn't it interesting how many people have a vested interest ("academic" careers, tourist trade etc) in keeping the pot boiling (just like the JFK saga)? I wonder would the almighty $ have something to do with all this?
C. Magee, USA

To tell you the truth, the more I read about the Roswell incident the more I think that there is something out there. I just can't believe that we are the only living thing in the universe. It has been proven that there was once life on mars, so there must be life somewhere else as well. Maybe I've been watching the X-Files and Star Trek for too long, but still, there must be something somewhere.
Anntoinette Weaver, Netherlands

As a sceptic and an engineer I saw a so-called flying saucer several years ago. In December 1991 I was walking with two friends at night along a beach in India. I made a comment about the full moon because it helped us see where we were walking. We walked on for a minute or so then one of my friends said "But wasn't there a full moon just two weeks ago?". We all then stopped and looked up. Suddenly the moon moved very quickly across the sky in a perfect horizontal line, paused, then shot up towards space. We live in a technology driven world where anything is possible. Roswell is possible.
Phillip Cresswell, Netherlands

In 1961 I was in Canada on vacation and was taken on board a flying saucer. I was aboard the flying saucer while it was in combat. I am certain that the Roswell incident is genuine. The flying saucers come from an intergalactic empire. They can travel at the velocity of light and go through hyperspacial transit to any place in the universe.
Paul Brown, Miami, Florida

The Roswell incident is just another case where resonable explanations are ignored for the want of the wish that we have had vistitors. And please don't mention the autopsey video - Dr Who had better effects than that.
Stuart Bushell, UK

As far as the Roswell mystery goes I certainly wouldn't put it past the American military to commit such a cover up. I certainly think that something other than a weather balloon crashed at Roswell. But on the other hand could this have been some experiment that went horribly wrong.
Kenneth James Gilmour, Queensland, Australia

I believe something definitely crashed there which was not a weather balloon, and which had abnormal occupants. Whether these occpants were extra-terrestrials or not is the key for me. I used to definitely believe they were, but these days I'm not so sure they weren't some kind of genetic experiment by the US. On the other hand though, it's funny how most of the stories/explanations seem on one level to fit nicely into established frameworks of folklore and belief systems. To me this suggests whatever it is that's really going on is being distorted to fit some place in modern folklore.
Ewen Cameron, Scotland