Excitable reports that the search for a radio signal from ET has paid off were dismissed as premature by astronomers involved in the search for extra-terrestrial intelligence (Seti).
The tantalising claim that a signal picked up by the Arecibo radio telescope three times for a total of less than a minute last year could be the best candidate yet for success in the six-year Seti@home project, in which a screensaver program on millions of home computers sifts through raw data, appeared in New Scientist magazine.
But Dan Wertheimer, the project's chief scientist and a radio astronomer at the University of Cailfornia, Berkeley, who was quoted by the magazine as saying "it's the most interesting signal from Seti@home", told BBC News Online: "It's all hype and noise. We have nothing that is unusual. It's all out of proportion."
The signal, named SHGbo2+14a, has a frequency of about 1420MHz, one of the main frequencies at which hydrogen, the most common element in the universe, absorbs and emits energy. Some scientists say aliens trying to introduce themselves would be likely to transmit at this frequency.
Computers running in the US and Germany detected the signal, which appears to be coming from between the constellations Pisces and Aries, where there is no obvious star or planetary system within 1,000 light years. It has a rapidly fluctuating frequency, which could occur if it was beamed out from a rapidly spinning planet or object, although a planet would have to be rotating nearly 40 times faster than Earth to produce the same drift.
A drifting signal would be expected to have a different frequency each time it was detected. Yet with every observation of SHGbo2+14a, the signal has started off with a frequency of 1420MHz before starting to drift - although this could be connected to the telescope.
Speaking from the Aricebo site in Puerto Rico, Dr Wertheimer added: "We have no candidates that we are particularly excited about." After analysing 50 trillion frequency bands, he added, it was not surprising that a signal like SHGbo2+14a should occur by chance.