They came from outer space! (Or possibly Panama?)

Aliens are back in vogue. This time it's not just computer-generated wizardry and science fiction plots about good versus evil, but an exploration of the human race's general mistrust of "others" or anything that doesn't fit in with our concept of the norm. It doesn't really matter whether you believe in them: how we think of aliens, and the things we "de-humanise", tells us a lot about ourselves.

The latest blockbuster movie, District 9, takes an honest hard look at themes of racism, xenophobia and apartheid in the relationship between man and aliens-turned-refugees. Meanwhile, in the real world, the current internet mania is over a grey, hairless, odd-looking "monster" discovered and killed by a group of teenagers in Cerro Azul, Panama. One of my friends who watched District 9 says: "It is reflective of the Palestinian refugee plight and any refugees walled in and isolated living in camps, who are dehumanised," echoing statements made by other viewers and critics.

For those who haven't seen it, the film starts with an alien spaceship stranded over the South African city of Johannesburg. The aliens, insultingly referred to as "prawns", are separated from the human population and locked up in a government camp known as District 9. When the authorities try to relocate the extraterrestrials even further away from humans, the story becomes interesting and multilayered.

The "Panama Monster", of course, could turn out to be another yeti or Loch Ness Monster, but even if it turns out to be a hoax, the creature is gaining a lot of sympathy. Bloggers are criticising the behaviour of the teenagers who killed it as "typical" of human cruelty towards anything "strange". "It looked small and harmless, why did it have to be killed?" one wrote. There's nothing new in that, however: let's not forget how the world fell in love with, in my opinion, a quite unattractive alien by the name of ET in 1982.

I first found out how seriously governments take UFOs and extraterrestrial sightings when I put in a request to the Canadian government for papers relating to this issue from the 1960s to the 1990s. I got three whole boxes of documents, many with "Confidential" stamped across them and with some pages blacked out or removed. What I treated at first as a joke turned into an interesting study of human psychology, conspiracy, and multiple interpretations of the same information. I found several "experts" who could comment on the issue, which made me realise that there is a whole world out there devoted to this kind of thing (what this thing actually is being a matter of interpretation).

One UFO expert told me at the time: "Yes, people make fun of us and we always get faxes and e-mails telling us to get a life and see a shrink. Nobody takes us seriously." This particular expert was a former pilot in the Canadian army, with a multinational staff of scientists and psychologists. It was a difficult story to write, so out of this world that I didn't know how to keep my objectivity. There was one report about several families in a town in the Canadian province of Alberta one winter in the 1970s, who said they had seen exactly the same phenomenon as families in another town in a different province. They described it as a "fat alien" with bright eyes who was peeking through windows, and tampering with people's TV reception. They all reported how the TV would "turn on and turn off on its own".

Many of the documents I reviewed were eyewitness reports by pilots who said they had seen a "strange object", usually circular, flying over them or next to them. A colleague in Moscow told me she had a stack of similar reports from Russia. It seems that whatever culture or background a person is from, there is a genuine interest and debate over aliens. When the subject came up in class at my school in Saudi Arabia, one of my religion teachers said that according to the Quran there are many unknown galaxies and creations of Allah out there. "So you never know. Who says we are the only ones around?" she said in all seriousness. No one ever brought up that issue again.

Whatever the case, whether you believe in them or not, or find them weird or amusing, there will always be reports and movies about aliens. Anything unexplained remains interesting by virtue of its mystery. @Email:[e-mail]