`Aliens' may exist, but encounters may be catastrophic: Hawking

Renowned physicist Stephen Hawking is clearly no ET enthusiast. The 68-year old, paralysed by motor neurone disease, believes that intelligent aliens probably exist but close encounters with them may likely lead to unfortunate consequences for us.

Promoting a new documentary he has made for the Discovery Channel, the legendary scientist told the Times that to his mathematical brain, the numbers alone made thinking about aliens perfectly rational. He said if aliens were to ever pay a visit to meet earthlings, it would have much the same consequences for us as Christopher Columbus' landing in America had for the native Americans.

According to the Times, the show would feature speculative scenes of alien life in extraterrestrial habitats, including some - in our own solar system possibly the hot oceans of Europa, one of Jupiter's moons.

According to Hawking, much of alien life would likely be on the same development scale as has existed on earth for almost all the time it has supported life- microbes or simple animal forms.

However, given the hundred billion galaxies each with potentially a hundred billion stars, Hawking believes intelligent life is entirely possible even perhaps intelligent life with such advanced technology as to allow travel across interstellar distances.

In his view, it would be extremely unwise on our part to attract the attention of such voyagers by such efforts as the practice of beaming out "Active SETI" signals.