The urban legend goes something like this: In June 1947, an extra-terrestrial spaceship crashes in Roswell, New Mexico. The debris is hastily recovered by the US Government and the ship's alien passengers are held captive in a secret military location, known only as Area 51.
The Roswell UFO incident has fuelled endless debate. Some believe Washington is covering up a genuine run-in with alien life, while others see something even more sinister, dark and conspiratorial.
Throughout, the US government has steadfastly refused to comment on the existence of aliens or any secret locations. Until now.
On Monday, in response to a petition submitted to the White House's website, the Obama administration released a statement carving out the official position: the US doesn't have and never had evidence of aliens.
Some might say that the petition's signatories, and the alien-seeking public in general, don't exactly help themselves. Thousands of fake abduction claims are made each year. One woman, when asked to describe the alien ship she claimed to have seen, said that it had the letters "UFO" on its side.
It is hardly surprising then that the US government is simply sticking to a well-worn line. But then again, if Uncle Sam were harbouring little green men in the desert, it would be one secret worth keeping.
