SETI detects intriguing signal

In February 2003, astronomers involved in the search for extraterrestrial intelligence (SETI) pointed the massive radio telescope in Arecibo, Puerto Rico, at around 200 sections of the sky. The same telescope had previously detected unexplained radio signals at least twice from each of these regions, and the astronomers were trying to reconfirm the findings. The team has now finished analysing the data, and all the signals seem to have disappeared. Except one, which has got stronger.

From New Scientist:

Not long ago, in a galaxy far away…

In February 2003, astronomers involved in the search for extraterrestrial intelligence (SETI) pointed the massive radio telescope in Arecibo, Puerto Rico, at around 200 sections of the sky. The same telescope had previously detected unexplained radio signals at least twice from each of these regions, and the astronomers were trying to reconfirm the findings.

The team has now finished analysing the data, and all the signals seem to have disappeared.

Except one, which has got stronger.

This radio signal, now seen on three separate occasions, is an enigma. It could be generated by a previously unknown astronomical phenomenon. Or it could be something much more mundane, maybe an artefact of the telescope itself.

But it also happens to be the best candidate yet for a contact by intelligent aliens in the nearly six-year history of the SETI@home project, which uses programs running as screensavers on millions of personal computers worldwide to sift through signals picked up by the Arecibo telescope.

”It’s the most interesting signal from SETI@home,” says Dan Wertheimer, a radio astronomer at the University of California, Berkeley (UCB) and the chief scientist for SETI@home. ”We’re not jumping up and down, but we are continuing to observe it.” Named SHGb02+14a, the signal has a frequency of about 1420 megahertz. This happens to be one of the main frequencies at which hydrogen, the most common element in the universe, readily absorbs and emits energy. Some astronomers have argued that extraterrestrials trying to advertise their presence would be likely to transmit at this frequency, and SETI researchers conventionally scan this part of the radio spectrum.

SHGb02+14a seems to be coming from a point between the constellations Pisces and Aries where there is no obvious star or planetary system within 1000 light years. And the transmission is very weak. ”We are looking for something that screams out ‘artificial’,” says UCB researcher Eric Korpela, who completed the analysis of the signal in April. ”This just doesn’t do that, but it could be because it is distant.”

The telescope has only observed the signal for about a minute in total, which is not long enough for astronomers to analyse it thoroughly. But, Korpela thinks it unlikely SHGb02+14a is the result of any obvious radio interference or noise, and it does not bear the signature of any known astronomical object. That doesn’t mean that only aliens could have produced it. ”It may be a natural phenomenon of a previously undreamed-of kind like I stumbled over,” says Jocelyn Bell Burnell of the University of Bath, UK.