I never believed in UFOs, until I saw one. I was driving home through Surrey one winter's evening in 1997, when I saw a luminous orange object floating in the distance above the trees. It was the classic UFO shape, like a cigar, and it appeared eerie and otherworldly, almost as if it was translucent. Suddenly, it took a smart leap to the left, stopped and zoomed upwards. Then it disappeared and reappeared lower. I didn't know of any aircraft that behaves like that.

I was absolutely terrified, not because of imminent alien invasion but because I was going to have to throw a lifetime of scepticism out of the window. I trembled as I thought of myself on daytime TV shows with the worst allies in the world - Kansas farmers, mullet-sporting crop circle fiends, camouflage-clad conspiracy theorists. After years of shooting at these easy targets, I was going to have to start sticking up for them.

I stopped the car and looked at the object from a layby in absolute wonder. All around me, others were doing the same. It came nearer and the thought: “Look, I can bear being a UFO believer, Lord, but don't make me have to say I was abducted too,” crossed my mind.

As it came closer, I saw it had writing on the side. “Orange”. It was a blimp, lit up to advertise the mobile phone company. If I'd kept driving then I might have been convinced to this day that I'd seen a UFO. Airships just don't jump about in the sky. But, viewed through trees from a moving car on a bumpy road, this one did.

Psychologists have often pointed out that witness statements are unreliable and that people see what they want to see. I now know that to be true - because, for ten minutes in 1997, I was that unreliable witness.

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